Atypical Neuropsychiatric Presentation of FTD-ALS Caused by a Pathogenic Repeat Expansion in C9orf72: A Case Report.

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.

Front row seat: The role MMI assessors play in widening access to medical school.

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.

Atypical variants in COL1A1 and COL3A1 associated with classical and vascular Ehlers-Danlos syndrome overlap phenotypes: expanding the clinical phenotype based on additional case reports.

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.

SMAD3 pathogenic variants: risk for thoracic aortic disease and associated complications from the Montalcino Aortic Consortium.

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.

Grange syndrome due to homozygous YY1AP1 missense rare variants.

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.

A mutation update on the LDS-associated genes TGFB2/3 and SMAD2/3.

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.

Germline mutations in MAP3K6 are associated with familial gastric cancer.

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.

Gastrointestinal Findings in the Largest Series of Patients With Hereditary Biallelic Mismatch Repair Deficiency Syndrome: Report from the International Consortium.

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.

Syndrome of hepatic cirrhosis, dystonia, polycythemia, and hypermanganesemia caused by mutations in SLC30A10, a manganese transporter in man.

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.

Phenotypic and molecular characterization of 19q12q13.1 deletions: a report of five patients.

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.

The mental health and traumatic experiences of mothers of children with 22q11DS.

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.

Mutations in centrosomal protein CEP152 in primary microcephaly families linked to MCPH4.

Primary microcephaly is a rare condition in which brain size is substantially diminished without other syndromic abnormalities. Seven autosomal loci have been genetically mapped, and the underlying causal genes have been identified for MCPH1, MCPH3, MCPH5, MCPH6, and MCPH7 but not for MCPH2 or MCPH4. The known genes play roles in mitosis and cell division. We ascertained three families from an Eastern Canadian subpopulation, each with one microcephalic child. Homozygosity analysis in two families using genome-wide dense SNP genotyping supported linkage to the published MCPH4 locus on chromosome 15q21.1. Sequencing of coding exons of candidate genes in the interval identified a nonconservative amino acid change in a highly conserved residue of the centrosomal protein CEP152. The affected children in these two families were both homozygous for this missense variant. The third affected child was compound heterozygous for the missense mutation plus a second, premature-termination mutation truncating a third of the protein and preventing its localization to centrosomes in transfected cells. CEP152 is the putative mammalian ortholog of Drosphila asterless, mutations in which affect mitosis in the fly. Published data from zebrafish are also consistent with a role of CEP152 in centrosome function. By RT-PCR, CEP152 is expressed in the embryonic mouse brain, similar to other MCPH genes. Like some other MCPH genes, CEP152 shows signatures of positive selection in the human lineage. CEP152 is a strong candidate for the causal gene underlying MCPH4 and may be an important gene in the evolution of human brain size.

Mutation in the gene encoding ubiquitin ligase LRSAM1 in patients with Charcot-Marie-Tooth disease.

Charcot-Marie-Tooth disease (CMT) represents a family of related sensorimotor neuropathies. We studied a large family from a rural eastern Canadian community, with multiple individuals suffering from a condition clinically most similar to autosomal recessive axonal CMT, or AR-CMT2. Homozygosity mapping with high-density SNP genotyping of six affected individuals from the family excluded 23 known genes for various subtypes of CMT and instead identified a single homozygous region on chromosome 9, at 122,423,730-129,841,977 Mbp, shared identical by state in all six affected individuals. A homozygous pathogenic variant was identified in the gene encoding leucine rich repeat and sterile alpha motif 1 (LRSAM1) by direct DNA sequencing of genes within the region in affected DNA samples. The single nucleotide change mutates an intronic consensus acceptor splicing site from AG to AA. Direct analysis of RNA from patient blood demonstrated aberrant splicing of the affected exon, causing an obligatory frameshift and premature truncation of the protein. Western blotting of immortalized cells from a homozygous patient showed complete absence of detectable protein, consistent with the splice site defect. LRSAM1 plays a role in membrane vesicle fusion during viral maturation and for proper adhesion of neuronal cells in culture. Other ubiquitin ligases play documented roles in neurodegenerative diseases. LRSAM1 is a strong candidate for the causal gene for the genetic disorder in our kindred.

Maternal age-based prenatal screening for chromosomal disorders: attitudes of women and health care providers toward changes.

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.

Mutation in pyrroline-5-carboxylate reductase 1 gene in families with cutis laxa type 2.

Autosomal-recessive cutis laxa type 2 (ARCL2) is a multisystem disorder characterized by the appearance of premature aging, wrinkled and lax skin, joint laxity, and a general developmental delay. Cutis laxa includes a family of clinically overlapping conditions with confusing nomenclature, generally requiring molecular analyses for definitive diagnosis. Six genes are currently known to mutate to yield one of these related conditions. We ascertained a cohort of typical ARCL2 patients from a subpopulation isolate within eastern Canada. Homozygosity mapping with high-density SNP genotyping excluded all six known genes, and instead identified a single homozygous region near the telomere of chromosome 17, shared identically by state by all genotyped affected individuals from the families. A putative pathogenic variant was identified by direct DNA sequencing of genes within the region. The single nucleotide change leads to a missense mutation adjacent to a splice junction in the gene encoding pyrroline-5-carboxylate reductase 1 (PYCR1). Bioinformatic analysis predicted a pathogenic effect of the variant on splice donor site function. Skipping of the associated exon was confirmed in RNA from blood lymphocytes of affected homozygotes and heterozygous mutation carriers. Exon skipping leads to deletion of the reductase functional domain-coding region and an obligatory downstream frameshift. PYCR1 plays a critical role in proline biosynthesis. Pathogenicity of the genetic variant in PYCR1 is likely, given that a similar clinical phenotype has been documented for mutation carriers of another proline biosynthetic enzyme, pyrroline-5-carboxylate synthase. Our results support a significant role for proline in normal development.

Performance of Black and Indigenous applicants in a medical school admissions process.

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.

Association of De Novo RNF213 Variants With Childhood Onset Moyamoya Disease and Diffuse Occlusive Vasculopathy.

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.

A family with Classical Ehlers-Danlos Syndrome (cEDS), mild bone fragility and without vascular complications, caused by the p.Arg312Cys mutation in COL1A1.

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.