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1.
Eur J Psychotraumatol ; 15(1): 2353532, 2024.
Article in English | MEDLINE | ID: mdl-38780146

ABSTRACT

Background: 22q11 Deletion Syndrome (22q11DS) is the most common microdeletion syndrome with broad phenotypic variability, leading to significant morbidity and some mortality. The varied health problems associated with 22q11DS and the evolving phenotype (both medical and developmental/behavioural) across the lifespan can strongly impact the mental health of patients as well as their caregivers. Like caregivers of children with other chronic diseases, caregivers of children with 22q11DS may experience an increased risk of traumatisation and mental health symptoms.Objective: The study's primary objective was to assess the frequency of traumatic experiences and mental health symptoms among mothers of children with 22q11DS. The secondary objective was to compare their traumatic experiences to those of mothers of children with other neurodevelopmental disorders (NDDs).Method: A total of 71 mothers of children diagnosed with 22q11DS completed an online survey about their mental health symptoms and traumatic experiences. Descriptive statistics were used to summarise the prevalence of their mental health symptoms and traumatic experiences. Logistic regression models were run to compare the traumatic experiences of mothers of children with 22q11DS to those of 335 mothers of children with other neurodevelopmental disorders (NDDs).Results: Many mothers of children with 22q11DS experienced clinically significant mental health symptoms, including depression (39%), anxiety (25%), and post-traumatic stress disorder (PTSD) symptoms (30%). The types of traumatic events experienced by mothers of children with 22q11DS differed from those of mothers of children with other NDDs as they were more likely to observe their child undergoing a medical procedure, a life-threatening surgery, or have been with their child in the intensive care unit.Conclusion: 22q11DS caregivers are likely to require mental health support and trauma-informed care, tailored to the specific needs of this population as they experience different kinds of traumatic events compared to caregivers of children with other NDDS.


Mothers of children with 22q11DS experience clinically significant levels of depression, anxiety, and PTSD.Mothers of children with 22q11DS experience many and diverse trauma particularly related to medical interventions of their child.The types of traumatic events experienced by mothers of children with 22q11DS are different from those of the mothers of children with other neurodevelopmental disorders.


Subject(s)
Mothers , Humans , Female , Mothers/psychology , Adult , Child , Male , Surveys and Questionnaires , Mental Health , Stress Disorders, Post-Traumatic/psychology , 22q11 Deletion Syndrome/psychology , Adolescent , Neurodevelopmental Disorders/psychology , Middle Aged , Caregivers/psychology
2.
J Geriatr Psychiatry Neurol ; 37(2): 157-162, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37548032

ABSTRACT

The case report describes the presentation of a 42-year-old male ultimately diagnosed with FTD-ALS caused by a genetic mutation, who initially presented with atypical psychiatric symptoms. Given that the initial clinical manifestations of FTD-ALS can be quite variable, the diagnosis is often challenging; the case report aims to highlight several key considerations in the diagnostic assessment, including genetic testing in order to guide clinicians in more timely diagnosis and ultimately improve patient care.


Subject(s)
Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Humans , Male , Amyotrophic Lateral Sclerosis/diagnosis , Amyotrophic Lateral Sclerosis/genetics , C9orf72 Protein/genetics , DNA Repeat Expansion , Frontotemporal Dementia/diagnosis , Frontotemporal Dementia/genetics , Mutation , Adult
3.
Med Teach ; 46(8): 1052-1059, 2024 08.
Article in English | MEDLINE | ID: mdl-38100759

ABSTRACT

BACKGROUND: While many medical schools utilize the Multiple Mini-Interview (MMI) to help select a diverse student body, we know little about MMI assessors' roles. Do MMI assessors carry unique insights on widening access (WA) to medical school? Herein we discuss the hidden expertise and insights that assessors contribute to the conversation around WA. METHODS: Ten MMI assessors (1-10 years' experience) participated in semi-structured interviews exploring factors influencing equitable medical school recruitment. Given their thoughtfulness during initial interviews, we invited them for follow-up interviews to gain further insight into their perceived role in WA. Fourteen interviews were conducted and analyzed using a thematic analysis approach. RESULTS: Assessors expressed concerns with diversity in medicine; dissatisfaction with the status quo fueled their contributions to the selection process. Assessors advocated for greater diversity among the assessor pool, citing benefits for all students, not only those from underrepresented groups. They noted that good intentions were not enough and that medical schools can do more to include underrepresented groups' perspectives in the admissions process. CONCLUSION: Our analysis reveals that MMI assessors are committed to WA and make thoughtful contributions to the selection process. A medical school selection process, inclusive of assessors' expertise is an important step in WA.


Subject(s)
Cultural Diversity , Interviews as Topic , School Admission Criteria , Schools, Medical , Humans , Students, Medical/psychology , Female , Male
4.
Clin Exp Rheumatol ; 40 Suppl 134(5): 46-62, 2022 May.
Article in English | MEDLINE | ID: mdl-35587586

ABSTRACT

The vast majority of reported (likely) pathogenic missense variants in the genes coding for the fibrillar collagens leads to the substitution of one of the obligatory glycine residues in the Gly-Xaa-Yaa repeat sequence of the triple helical domain. Their phenotypic consequences and deleterious effects have been well-documented. However, with increasing access to molecular diagnostic testing based on next-generation sequencing techniques, such as sequencing of multi-gene panels and whole-exome sequencing, non-glycine substitutions are more frequently identified in individuals suspected to have a heritable collagen disorder, but their pathogenic effect is often difficult to predict.Some specific non-glycine substitutions in the proα1(I)- (p.(Arg312Cys)) and proα1(III)- (glutamic acid to lysine at different positions) collagen chain have been identified in a number of individuals presenting a phenotype showing features of both classical and vascular Ehlers-Danlos syndrome. The number of reported individuals with these defects is currently very low, and several of these non-glycine substitutions had initially been categorised as variants of unknown significance (VUS), complicating early diagnosis, accurate counselling, management guidelines, and correct classification. This collaborative study reports on the phenotype of 22 and 7 individuals harbouring these rare variants in COL1A1 and COL3A1, respectively, expanding our knowledge on clinical presentation, phenotypic variability, and natural history, and informing on the risk for potentially life-threatening events, such as vascular, gastro-intestinal, and pregnancy-related complications.


Subject(s)
Collagen Type I, alpha 1 Chain , Ehlers-Danlos Syndrome , Collagen , Collagen Type III/genetics , Ehlers-Danlos Syndrome/complications , Ehlers-Danlos Syndrome/diagnosis , Ehlers-Danlos Syndrome/genetics , Humans , Mutation , Phenotype
5.
Neurology ; 96(13): e1783-e1791, 2021 03 30.
Article in English | MEDLINE | ID: mdl-33568546

ABSTRACT

OBJECTIVE: To test the hypothesis that de novo genetic variants are responsible for moyamoya disease (MMD) in children with unaffected relatives, we performed exome sequencing of 28 affected children and their unaffected parents. METHODS: Exome sequencing was performed on 28 trios of affected patients with MMD and unaffected parents. RESULTS: We identified 3 novel rare de novo RNF213 variants, 1 in the RING domain and 2 in a highly conserved region distal to the RING domain (4,114-4,120). These de novo cases of MMD present at a young age with aggressive MMD and uniquely have additional occlusive vascular lesions, including renal artery stenosis. Two previously reported cases had de novo variants in the same limited region and presented young with aggressive MMD, and 1 case had narrowing of the inferior abdominal aorta. CONCLUSIONS: These results indicate a novel syndrome associated with RNF213 rare variants defined by de novo mutations disrupting highly conserved amino acids in the RING domain and a discrete region distal to the RING domain delimited by amino acids 4,114 to 4,120 leading to onset of severe MMD before 3 years of age and occlusion of other arteries, including the abdominal aorta, renal, iliac, and femoral arteries.


Subject(s)
Adenosine Triphosphatases/genetics , Moyamoya Disease/genetics , Ubiquitin-Protein Ligases/genetics , Adult , Age of Onset , Aortic Diseases/genetics , Aortic Diseases/physiopathology , Arterial Occlusive Diseases/genetics , Arterial Occlusive Diseases/physiopathology , Child, Preschool , Female , Femoral Artery , Humans , Iliac Artery , Male , Moyamoya Disease/physiopathology , Mutation , Renal Artery Obstruction/genetics , Renal Artery Obstruction/physiopathology
6.
Can Med Educ J ; 12(6): 35-42, 2021 Dec.
Article in English | MEDLINE | ID: mdl-35003429

ABSTRACT

BACKGROUND: Diversity in medical schools has lagged behind Canada's growing multicultural population. Dalhousie medical school allows Black and Indigenous applicants to self-identify. We examined how these applicants performed and progressed through the admissions process compared to Other group (applicants who did not self-identify). METHODS: Retrospective analysis of four application cycles (2015-2019) was conducted, comparing demographic data, scores for application components (Computer-Based Assessment for Sampling Personal Characteristics (CASPer), MCAT, GPA, supplemental, discretionary, Multiple Mini Interview (MMI)), and final application status between the three groups. RESULTS: Of 1322 applicants, 104 identified as Black, 64 Indigenous, and 1154 Other. GPA was higher in the Other compared to the Indigenous group (p < 0.001). CASPer score was higher in the Other compared to the Black group (p = 0.047). There was no difference between groups for all other application components. A large proportion of Black and Indigenous applicants had incomplete applications. Acceptance rates were similar between all groups. Black applicants declined an admission offer substantially more than expected (31%; p < 0.001). CONCLUSIONS: Black and Indigenous applicants who completed their application progressed well through the admissions process. The pool of diverse applicants needs to be increased and support provided for completion of applications. Further study is warranted to understand why qualified applicants decline acceptance.


CONTEXTE: Les facultés de médecine ne reflètent pas la diversité croissante de la population multiculturelle du Canada. Celle de l'Université Dalhousie invite les candidats à déclarer s'ils se définissent comme une personne noire ou autochtone. Nous avons fait un examen comparatif du comportement et de la progression dans le processus d'admission des candidats qui ont déclaré leur appartenance à un de ces groupes et des candidats qui ne l'ont pas fait (groupe Autre). MÉTHODES: Nous avons fait une analyse rétrospective de quatre cycles de candidatures (2015-2019), en comparant les données démographiques, les scores des composantes de la candidature (examen assisté par ordinateur pour l'échantillonnage des caractéristiques personnelles ou CASPer, MCAT, MPC, renseignements complémentaires, décision discrétionnaire, mini-entrevues multiples (MEM)) et le statut final de la candidature des trois groupes. RÉSULTATS: Parmi les 1 322 candidats, 104 se sont définis comme étant Noirs, 64 comme Autochtones et 1 154 ont coché « Autre ¼. La moyenne cumulative du groupe Autre était plus élevée que celle du groupe Personne autochtone (p<0,001). Le score CASPer du groupe Autre était plus élevé que celui du groupe Personne noire (p=0,047). Pour tous les autres éléments de la candidature, il n'y avait pas de différence entre les groupes. Un grand nombre de candidats noirs et autochtones avaient des dossiers incomplets. Les taux d'acceptation des trois groupes étaient similaires. Le nombre de candidats noirs qui ont refusé une offre d'admission était beaucoup plus élevé que prévu (31 %; p<0,001). CONCLUSIONS: Les candidats noirs et autochtones dont le dossier était complet ont bien cheminé dans le processus d'admission. Il convient d'élargir le bassin de candidats de diverses origines et de leur proposer de l'aide pour remplir la demande d'admission. D'autres études sont nécessaires pour comprendre pourquoi les candidats sélectionnés refusent une offre d'admission.

8.
Eur J Med Genet ; 63(2): 103730, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31323331

ABSTRACT

The Ehlers-Danlos syndromes (EDS) are heritable disorders of connective tissue (HDCT) with joint hypermobility, skin hyperextensibility and tissue fragility, which were recently re-classified (2017 International Classification). Most patients (>90%) with Classical Ehlers-Danlos syndrome (cEDS) have a mutation in the COL5A1 or COL5A2 genes encoding type V procollagen. A small number of patients with the p.Arg312Cys mutation in COL1A1 have been reported with overlapping features of both cEDS and vascular EDS (vEDS). In this report, we describe two patients from a large family with this mutation and clinical features consistent with cEDS without vascular complications. The proband presented with congenital hip dislocation (previously reported in one patient), the mother of the proband with multiple fractures in childhood, and dental defects (novel findings). The small number of patients reported with this mutation and proportion with vascular complications suggests that vascular surveillance should still be recommended.


Subject(s)
Collagen Type I/genetics , Ehlers-Danlos Syndrome/diagnosis , Ehlers-Danlos Syndrome/genetics , Adolescent , Adult , Bone and Bones/pathology , Collagen Type I, alpha 1 Chain , Ehlers-Danlos Syndrome/diagnostic imaging , Female , Fractures, Bone/genetics , Humans , Mutation , Pedigree , Phenotype , Skin Abnormalities/genetics
9.
Matrix Biol ; 88: 1-18, 2020 06.
Article in English | MEDLINE | ID: mdl-31726086

ABSTRACT

Weill-Marchesani syndrome (WMS) is a rare genetic disorder that affects the musculoskeletal system, the eye, and the cardiovascular system. Individuals with WMS present with short stature, joint contractures, thick skin, microspherophakia, small and dislocated lenses, and cardiac valve anomalies. WMS can be caused by recessive mutations in ADAMTS10 (WMS 1), ADAMTS17 (WMS 4), or LTBP2 (WMS 3), or by dominant mutations in fibrillin-1 (FBN1) (WMS 2); all genes encode secreted extracellular matrix (ECM) proteins. Individuals with WMS 4 due to ADAMTS17 mutations appear to have less severe cardiac involvement and present predominantly with the musculoskeletal and ocular features of WMS. ADAMTS17 is a member of the ADAMTS family of secreted proteases and directly binds to fibrillins. Here we report a novel pathogenic variant in ADAMTS17 that causes WMS 4 in an individual with short stature, brachydactyly, and small, spherical, and dislocated lenses. We provide biochemical and cell biological insights in the pathomechanisms of WMS 4, which also suggest potential biological functions for ADAMTS17. We show that the variant in ADAMTS17 prevents its secretion and we found intracellular accumulation of fibrillin-1 and collagen type I in patient-derived skin fibroblasts. In accordance, transmission electron microscopy revealed elastic fiber abnormalities, decreased collagen fibril diameters, and intracellular collagen accumulation in the dermis of the proband. Together, the data indicate a possible role for ADAMTS17 in the secretion of fibrillin-1 and collagen type I or in their early assembly in the pericellular matrix or the ECM.


Subject(s)
ADAMTS Proteins/genetics , Collagen Type I/metabolism , Extracellular Matrix/metabolism , Fibrillin-1/metabolism , Polymorphism, Single Nucleotide , Weill-Marchesani Syndrome/genetics , ADAMTS Proteins/chemistry , ADAMTS Proteins/metabolism , Catalytic Domain , Cell Line , Dermis/cytology , Dermis/metabolism , Female , Fibroblasts/cytology , Fibroblasts/metabolism , HEK293 Cells , Humans , Microscopy, Electron, Transmission , Middle Aged , Models, Molecular , Pedigree , Weill-Marchesani Syndrome/metabolism
10.
Med Clin North Am ; 103(6): 1005-1019, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31582001

ABSTRACT

Heritable thoracic aortic disease (HTAD) can have life-threatening consequences if not diagnosed early. Affected individuals and at-risk family members benefit from both cardiology and genetic evaluations, including genetic testing. Important information can be obtained through family history, medical history, and genetic testing to help guide management and assess risk. A genetic diagnosis can guide cardiovascular management (type and frequency of vascular imaging, timing of surgical intervention), risk assessment for arterial aneurysm/dissection, evaluation of nonvascular features, and familial testing.


Subject(s)
Aorta, Thoracic/abnormalities , Aortic Diseases , Genetic Testing/methods , Patient Care Management/methods , Aortic Diseases/genetics , Aortic Diseases/therapy , Humans , Precision Medicine/methods
11.
Am J Med Genet A ; 179(12): 2500-2505, 2019 12.
Article in English | MEDLINE | ID: mdl-31633303

ABSTRACT

Grange syndrome (OMIM 602531) is an autosomal recessive condition characterized by severe early onset vascular occlusive disease and variable penetrance of brachydactyly, syndactyly, bone fragility, and learning disabilities. Grange syndrome is caused by homozygous or compound heterozygous loss-of-function variants in the YYA1P1 gene. We report on the case of a 53-year old female with novel homozygous missense variants in YYA1P1 (c.1079C>T, p.Pro360Leu), presenting with a history of brachysyndactyly, hypertension, and ischemic stroke. Imaging studies revealed stenosis of the bilateral internal carotid with extensive collateralization of cerebral vessels in a moyamoya-like pattern, along with stenosis in the splenic, common hepatic, celiac, left renal, and superior mesenteric arteries. Functional studies conducted with the patient's dermal fibroblasts suggest that the p.Pro360Leu variant decreases the stability of the YY1AP1 protein. This is the first report of a missense variant associated with Grange syndrome characterized by later onset of vascular disease and a lack of developmental delay and bone fragility.


Subject(s)
Arterial Occlusive Diseases/diagnosis , Arterial Occlusive Diseases/genetics , Bone and Bones/abnormalities , Brachydactyly/diagnosis , Brachydactyly/genetics , Cell Cycle Proteins/genetics , Genetic Association Studies , Genetic Predisposition to Disease , Heart Defects, Congenital/diagnosis , Heart Defects, Congenital/genetics , Homozygote , Hypertension/diagnosis , Hypertension/genetics , Mutation, Missense , Syndactyly/diagnosis , Syndactyly/genetics , Transcription Factors/genetics , Cell Line , Computed Tomography Angiography , Consanguinity , Female , Genetic Association Studies/methods , Humans , Male , Tomography, X-Ray Computed
12.
J Med Genet ; 56(4): 252-260, 2019 04.
Article in English | MEDLINE | ID: mdl-30661052

ABSTRACT

BACKGROUND: Pathogenic variants in SMAD3 cause thoracic aortic aneurysms and dissections, along with aneurysms and rupture of other arteries. Here, we examined differences in clinical presentation of aortic events (dissection or surgical repair of an aneurysm) with respect to age and variant type in an international cohort of individuals with SMAD3 variants. METHODS: Aortic status and events, vital status and clinical features were abstracted through retrospective review of medical records of 212 individuals with 51 unique SMAD3 variants, including haploinsufficiency (HI) and missense substitutions in the MH2 domain, as well as novel in-frame deletions and missense variants in the MH1 domain. RESULTS: Aortic events were documented in 37% of cases, with dissections accounting for 70% of events. The median age at first aortic event was significantly lower in individuals with SMAD3 MH2 missense variants than those with HI variants (42years vs 49 years; p=0.003), but there was no difference in frequency of aortic events by variant type. The cumulative risk of an aortic event was 50% at 54 years of age. No aortic events in childhood were observed. CONCLUSIONS: SMAD3 pathogenic variants cause thoracic aortic aneurysms and dissections in the majority of individuals with variable age of onset and reduced penetrance. Of the covariates examined, the type of underlying SMAD3 variant was responsible for some of this variation. Later onset of aortic events and the absence of aortic events in children associated with SMAD3 variants support gene-specific management of this disorder.


Subject(s)
Aortic Aneurysm, Thoracic/diagnosis , Aortic Aneurysm, Thoracic/genetics , Genetic Association Studies , Genetic Predisposition to Disease , Genetic Variation , Phenotype , Smad3 Protein/genetics , Adolescent , Adult , Aged , Alleles , Amino Acid Substitution , Aortic Aneurysm, Thoracic/complications , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Mutation , Prognosis , Protein Domains/genetics , Risk Factors , Smad3 Protein/chemistry
13.
Hum Mutat ; 39(5): 621-634, 2018 05.
Article in English | MEDLINE | ID: mdl-29392890

ABSTRACT

The Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting the cardiovascular, skeletal, and ocular system. Most typically, LDS patients present with aortic aneurysms and arterial tortuosity, hypertelorism, and bifid/broad uvula or cleft palate. Initially, mutations in transforming growth factor-ß (TGF-ß) receptors (TGFBR1 and TGFBR2) were described to cause LDS, hereby leading to impaired TGF-ß signaling. More recently, TGF-ß ligands, TGFB2 and TGFB3, as well as intracellular downstream effectors of the TGF-ß pathway, SMAD2 and SMAD3, were shown to be involved in LDS. This emphasizes the role of disturbed TGF-ß signaling in LDS pathogenesis. Since most literature so far has focused on TGFBR1/2, we provide a comprehensive review on the known and some novel TGFB2/3 and SMAD2/3 mutations. For TGFB2 and SMAD3, the clinical manifestations, both of the patients previously described in the literature and our newly reported patients, are summarized in detail. This clearly indicates that LDS concerns a disorder with a broad phenotypical spectrum that is still emerging as more patients will be identified. All mutations described here are present in the corresponding Leiden Open Variant Database.


Subject(s)
Genetic Association Studies , Loeys-Dietz Syndrome/genetics , Mutation/genetics , Smad2 Protein/genetics , Smad3 Protein/genetics , Transforming Growth Factor beta2/genetics , Transforming Growth Factor beta3/genetics , Animals , Disease Models, Animal , Humans , Loeys-Dietz Syndrome/diagnosis , Mice , Signal Transduction/genetics
15.
Am J Gastroenterol ; 111(2): 275-84, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26729549

ABSTRACT

OBJECTIVES: Hereditary biallelic mismatch repair deficiency (BMMRD) is caused by biallelic mutations in the mismatch repair (MMR) genes and manifests features of neurofibromatosis type 1, gastrointestinal (GI) polyposis, and GI, brain, and hematological cancers. This is the first study to characterize the GI phenotype in BMMRD using both retrospective and prospective surveillance data. METHODS: The International BMMRD Consortium was created to collect information on BMMRD families referred from around the world. All patients had germline biallelic MMR mutations or lack of MMR protein staining in normal and tumor tissue. GI screening data were obtained through medical records with annual updates. RESULTS: Thirty-five individuals from seven countries were identified with BMMRD. GI data were available on 24 of 33 individuals (73%) of screening age, totaling 53 person-years. The youngest age of colonic adenomas was 7, and small bowel adenoma was 11. Eight patients had 19 colorectal adenocarcinomas (CRC; median age 16.7 years, range 8-25), and 11 of 18 (61%) CRC were distal to the splenic flexure. Eleven patients had 15 colorectal surgeries (median 14 years, range 9-25). Four patients had five small bowel adenocarcinomas (SBC; median 18 years, range 11-33). Two CRC and two SBC were detected during surveillance within 6-11 months and 9-16 months, respectively, of last consecutive endoscopy. No patient undergoing surveillance died of a GI malignancy. Familial clustering of GI cancer was observed. CONCLUSIONS: The prevalence and penetrance of GI neoplasia in children with BMMRD is high, with rapid development of carcinoma. Colorectal and small bowel surveillance should commence at ages 3-5 and 8 years, respectively.


Subject(s)
Adenocarcinoma/surgery , Adenoma/surgery , Brain Neoplasms/physiopathology , Colorectal Neoplasms/surgery , Intestine, Small/surgery , Neoplastic Syndromes, Hereditary/physiopathology , Adaptor Proteins, Signal Transducing/genetics , Adenocarcinoma/etiology , Adenocarcinoma/genetics , Adenoma/etiology , Adenoma/genetics , Adenosine Triphosphatases/genetics , Adolescent , Adult , Alleles , Brain Neoplasms/complications , Brain Neoplasms/etiology , Brain Neoplasms/genetics , Child , Child, Preschool , Colorectal Neoplasms/complications , Colorectal Neoplasms/etiology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/physiopathology , DNA Repair Enzymes/genetics , DNA-Binding Proteins/genetics , Female , Germ-Line Mutation , Glioma/etiology , Humans , Intestinal Neoplasms/etiology , Intestinal Neoplasms/genetics , Intestinal Neoplasms/surgery , Kidney Neoplasms/etiology , Leukemia/etiology , Lymphoma/etiology , Male , Melanoma/etiology , Mismatch Repair Endonuclease PMS2 , MutL Protein Homolog 1 , Neoplastic Syndromes, Hereditary/complications , Neoplastic Syndromes, Hereditary/genetics , Nuclear Proteins/genetics , Phenotype , Prospective Studies , Retrospective Studies , Wilms Tumor/etiology , Young Adult
16.
PLoS Genet ; 10(10): e1004669, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25340522

ABSTRACT

Gastric cancer is among the leading causes of cancer-related deaths worldwide. While heritable forms of gastric cancer are relatively rare, identifying the genes responsible for such cases can inform diagnosis and treatment for both hereditary and sporadic cases of gastric cancer. Mutations in the E-cadherin gene, CDH1, account for 40% of the most common form of familial gastric cancer (FGC), hereditary diffuse gastric cancer (HDGC). The genes responsible for the remaining forms of FGC are currently unknown. Here we examined a large family from Maritime Canada with FGC without CDH1 mutations, and identified a germline coding variant (p.P946L) in mitogen-activated protein kinase kinase kinase 6 (MAP3K6). Based on conservation, predicted pathogenicity and a known role of the gene in cancer predisposition, MAP3K6 was considered a strong candidate and was investigated further. Screening of an additional 115 unrelated individuals with non-CDH1 FGC identified the p.P946L MAP3K6 variant, as well as four additional coding variants in MAP3K6 (p.F849Sfs*142, p.P958T, p.D200Y and p.V207G). A somatic second-hit variant (p.H506Y) was present in DNA obtained from one of the tumor specimens, and evidence of DNA hypermethylation within the MAP3K6 gene was observed in DNA from the tumor of another affected individual. These findings, together with previous evidence from mouse models that MAP3K6 acts as a tumor suppressor, and studies showing the presence of somatic mutations in MAP3K6 in non-hereditary gastric cancers and gastric cancer cell lines, point towards MAP3K6 variants as a predisposing factor for FGC.


Subject(s)
Genetic Predisposition to Disease , Germ-Line Mutation/genetics , MAP Kinase Kinase Kinases/genetics , Stomach Neoplasms/genetics , Antigens, CD , Cadherins/genetics , DNA Mutational Analysis , Female , Genetic Linkage , Genotype , Humans , Male , Pedigree , Polymorphism, Single Nucleotide , Stomach Neoplasms/pathology
17.
Am J Med Genet A ; 164A(1): 62-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24243649

ABSTRACT

A syndrome associated with 19q13.11 microdeletions has been proposed based on seven previous cases that displayed developmental delay, intellectual disability, speech disturbances, pre- and post-natal growth retardation, microcephaly, ectodermal dysplasia, and genital malformations in males. A 324-kb critical region was previously identified as the smallest region of overlap (SRO) for this syndrome. To further characterize this microdeletion syndrome, we present five patients with deletions within 19q12q13.12 identified using a whole-genome oligonucleotide microarray. Patients 1 and 2 possess deletions overlapping the SRO, and Patients 3-5 have deletions proximal to the SRO. Patients 1 and 2 share significant phenotypic overlap with previously reported cases, providing further definition of the 19q13.11 microdeletion syndrome phenotype, including the first presentation of ectrodactyly in the syndrome. Patients 3-5, whose features include developmental delay, growth retardation, and feeding problems, support the presence of dosage-sensitive genes outside the SRO that may contribute to the abnormal phenotypes observed in this syndrome. Multiple genotype-phenotype correlations outside the SRO are explored, including further validation of the deletion of WTIP as a candidate for male hypospadias observed in this syndrome. We postulate that unique patient-specific deletions within 19q12q13.1 may explain the phenotypic variability observed in this emerging contiguous gene deletion syndrome.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 19 , Phenotype , Abnormalities, Multiple/genetics , Adolescent , Child , Child, Preschool , Comparative Genomic Hybridization , Facies , Female , Genetic Diseases, Inborn/diagnosis , Genetic Diseases, Inborn/genetics , Humans , Infant , Male , Syndrome
18.
Can Fam Physician ; 59(1): e39-47, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23341678

ABSTRACT

OBJECTIVE: To explore views of women and health care providers (HCPs) about the changing recommendations regarding maternal age-based prenatal screening. DESIGN: Mixed-methods design. SETTING: Ontario. PARTICIPANTS: A sample of women who had given birth within the previous 2 years and who had attended a family medicine centre, midwifery practice, or baby and mother wellness program (n = 42); and a random sample of family physicians (n = 1600), and all Ontario obstetricians (n = 694) and midwives (n = 334) who provided prenatal care. METHODS: We used focus groups (FGs) to explore women's views. Content analysis was used to uncover themes and delineate meaning. To explore HCPs' views, we conducted a cross-sectional self-completion survey. MAIN FINDINGS: All FG participants (42 women in 6 FGs) expressed the importance of individual choice of prenatal screening modality, regardless of age. They described their perception that society considers women older than 35 to be at high obstetric risk and raised concerns that change in the maternal age-related screening policy would require education. The HCP survey response rate was 40%. Results showed 24% of HCPs agreed that women of any age should be eligible for invasive diagnostic testing regardless of prenatal screening results; 15% agreed that the age for diagnostic testing should be increased to 40 years, 14% agreed that diagnostic testing should be reserved for women with positive prenatal screening results, and 45% agreed that prenatal screening should remain unchanged. CONCLUSION: Maternity care organizations have recommended that maternal age-based prenatal screening is no longer appropriate. Informed choice is of paramount importance to women and should be part of any change. Health care providers need to be engaged in and educated about any change to screening guidelines to offer women informed choices.


Subject(s)
Attitude of Health Personnel , Chromosome Disorders/diagnosis , Genetic Testing/methods , Health Knowledge, Attitudes, Practice , Maternal Age , Prenatal Diagnosis/psychology , Adult , Cross-Sectional Studies , Family Practice/methods , Female , Focus Groups , Humans , Male , Middle Aged , Midwifery/methods , Obstetrics/methods , Patient Preference , Patient Selection , Practice Guidelines as Topic , Pregnancy , Prenatal Diagnosis/methods , Surveys and Questionnaires , Young Adult
19.
Am J Hum Genet ; 90(3): 457-66, 2012 Mar 09.
Article in English | MEDLINE | ID: mdl-22341972

ABSTRACT

Environmental manganese (Mn) toxicity causes an extrapyramidal, parkinsonian-type movement disorder with characteristic magnetic resonance images of Mn accumulation in the basal ganglia. We have recently reported a suspected autosomal recessively inherited syndrome of hepatic cirrhosis, dystonia, polycythemia, and hypermanganesemia in cases without environmental Mn exposure. Whole-genome mapping of two consanguineous families identified SLC30A10 as the affected gene in this inherited type of hypermanganesemia. This gene was subsequently sequenced in eight families, and homozygous sequence changes were identified in all affected individuals. The function of the wild-type protein and the effect of sequence changes were studied in the manganese-sensitive yeast strain Δpmr1. Expressing human wild-type SLC30A10 in the Δpmr1 yeast strain rescued growth in high Mn conditions, confirming its role in Mn transport. The presence of missense (c.266T>C [p.Leu89Pro]) and nonsense (c.585del [p.Thr196Profs(∗)17]) mutations in SLC30A10 failed to restore Mn resistance. Previously, SLC30A10 had been presumed to be a zinc transporter. However, this work has confirmed that SLC30A10 functions as a Mn transporter in humans that, when defective, causes Mn accumulation in liver and brain. This is an important step toward understanding Mn transport and its role in neurodegenerative processes.


Subject(s)
Cation Transport Proteins/genetics , Codon, Nonsense , Manganese Poisoning/genetics , Manganese/metabolism , Metabolic Diseases/genetics , Metabolic Diseases/metabolism , Mutation, Missense , Adolescent , Adult , Amino Acid Sequence , Brain/metabolism , Cation Transport Proteins/metabolism , Child , Child, Preschool , Chromosome Mapping/methods , Female , Genetic Predisposition to Disease , Humans , Liver/metabolism , Male , Manganese Poisoning/metabolism , Molecular Sequence Data , Saccharomyces cerevisiae/genetics , Sequence Alignment , Sequence Analysis, DNA , Young Adult , Zinc Transporter 8
20.
Nat Genet ; 43(4): 360-4, 2011 Feb 27.
Article in English | MEDLINE | ID: mdl-21358631

ABSTRACT

Meier-Gorlin syndrome is a rare autosomal recessive genetic condition whose primary clinical hallmarks include small stature, small external ears and small or absent patellae. Using marker-assisted mapping in multiple families from a founder population and traditional coding exon sequencing of positional candidate genes, we identified three different mutations in the gene encoding ORC4, a component of the eukaryotic origin recognition complex, in five individuals with Meier-Gorlin syndrome. In two such individuals that were negative for mutations in ORC4, we found potential mutations in ORC1 and CDT1, two other genes involved in origin recognition. ORC4 is well conserved in eukaryotes, and the yeast equivalent of the human ORC4 missense mutation was shown to be pathogenic in functional assays of cell growth. This is the first report, to our knowledge, of a germline mutation in any gene of the origin recognition complex in a vertebrate organism.


Subject(s)
Cell Cycle Proteins/genetics , Mutation , Origin Recognition Complex/genetics , Adolescent , Amino Acid Sequence , Base Sequence , Child , Child, Preschool , Congenital Microtia , Consanguinity , Conserved Sequence , DNA/genetics , Ear/abnormalities , Ear/pathology , Female , Founder Effect , Growth Disorders/genetics , Growth Disorders/pathology , Haplotypes , Humans , Male , Micrognathism/genetics , Micrognathism/pathology , Molecular Sequence Data , Patella/abnormalities , Patella/pathology , Pedigree , Polymorphism, Single Nucleotide , Sequence Homology, Amino Acid
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