ABSTRACT
Neurofibromatosis type 1 (NF1), a common genetic disorder with a birth incidence of 1:2,000-3,000, is characterized by a highly variable clinical presentation. To date, only two clinically relevant intragenic genotype-phenotype correlations have been reported for NF1 missense mutations affecting p.Arg1809 and a single amino acid deletion p.Met922del. Both variants predispose to a distinct mild NF1 phenotype with neither externally visible cutaneous/plexiform neurofibromas nor other tumors. Here, we report 162 individuals (129 unrelated probands and 33 affected relatives) heterozygous for a constitutional missense mutation affecting one of five neighboring NF1 codons-Leu844, Cys845, Ala846, Leu847, and Gly848-located in the cysteine-serine-rich domain (CSRD). Collectively, these recurrent missense mutations affect â¼0.8% of unrelated NF1 mutation-positive probands in the University of Alabama at Birmingham (UAB) cohort. Major superficial plexiform neurofibromas and symptomatic spinal neurofibromas were more prevalent in these individuals compared with classic NF1-affected cohorts (both p < 0.0001). Nearly half of the individuals had symptomatic or asymptomatic optic pathway gliomas and/or skeletal abnormalities. Additionally, variants in this region seem to confer a high predisposition to develop malignancies compared with the general NF1-affected population (p = 0.0061). Our results demonstrate that these NF1 missense mutations, although located outside the GAP-related domain, may be an important risk factor for a severe presentation. A genotype-phenotype correlation at the NF1 region 844-848 exists and will be valuable in the management and genetic counseling of a significant number of individuals.
Subject(s)
Codon/genetics , Genetic Association Studies , Mutation, Missense/genetics , Neurofibromatosis 1/genetics , Neurofibromin 1/genetics , Adolescent , Amino Acid Sequence , Child , Cohort Studies , Computer Simulation , Demography , Female , Heterozygote , Humans , Male , Neurofibromin 1/chemistry , Phenotype , Young AdultABSTRACT
In 2011, KIAA1033/WASHC4 was associated with autosomal recessive intellectual disability (ARID) in a large consanguineous family comprising seven affected individuals with moderate ID and short stature. Since then, no other cases of KIAA1033 variants have been reported. Here we describe three additional patients (from two unrelated families) with syndromic ID due to compound heterozygous KIAA1033 variants ascertained by exome sequencing (ES). Two sisters, aged 4 and 5.5 years, had a stop-gain and a missense variants, each inherited from one parent (p.(Gln442*) and p.(Asp1048Gly)). Both had learning disabilities, macrocephaly, dysmorphic features, skeletal anomalies, and subependymal heterotopic nodules. In addition, the younger sibling had a congenital absence of the right internal carotid and bilateral sensorineural hearing loss. The third patient was aged 34 years and had two missense variants, one inherited from each parent (p.(Lys1079Arg) and p.(His503Arg)). This patient presented with mild ID, short stature, and microcephaly. KIAA1033 encodes a large protein (WASHC4), which is part of the WASH complex. The WASH complex is involved in the regulation of the fission of tubules that serve as transport intermediates during endosome sorting. Another member of the WASH complex, KIAA0196/WASHC5, has already been implicated in ARID with brain and cardiac malformations, under the designation of 3C or Ritscher-Schinzel syndrome (MIM#20210). ES has proved efficient for finding replications of genes with insufficient data in the literature to be defined as new OMIM genes. We conclude that KIAA1033 is responsible for a heterogeneous ARID phenotype, and additional description will be needed to refine the clinical phenotype.
Subject(s)
Intellectual Disability/pathology , Intracellular Signaling Peptides and Proteins/genetics , Mutation , Adult , Child, Preschool , Female , Humans , Infant, Newborn , Intellectual Disability/genetics , Male , Pedigree , Phenotype , Protein Subunits/geneticsABSTRACT
At the Third Turner Resource Network Symposium, a working group presented the results of collaborative discussions about the importance of autopsy in Turner syndrome (TS). Considerable gaps in understanding the causes of death in TS can only be closed by more frequent death investigations and autopsies. The presentation included an overview of autopsy methods, strategies for utilizing autopsy, and biobanking to address research questions about TS, and the role of palliative care in the context of autopsy. This review highlights strategies to promote autopsy and tissue donation, culminating with an action plan to increase autopsy rates in the TS community.
Subject(s)
Autopsy/trends , Tissue and Organ Procurement/trends , Turner Syndrome/diagnosis , Autopsy/methods , Female , HumansABSTRACT
To address knowledge gaps about Turner syndrome (TS) associated disease mechanisms, the Turner Syndrome Society of the United States created the Turner Syndrome Research Registry (TSRR), a patient-powered registry for girls and women with TS. More than 600 participants, parents or guardians completed a 33-item foundational survey that included questions about demographics, medical conditions, psychological conditions, sexuality, hormonal therapy, patient and provider knowledge about TS, and patient satisfaction. The TSRR platform is engineered to allow individuals living with rare conditions and investigators to work side-by-side. The purpose of this article is to introduce the concept, architecture, and currently available content of the TSRR, in anticipation of inviting proposals to utilize registry resources.
Subject(s)
Registries , Research/organization & administration , Turner Syndrome , Female , Humans , Male , Parents , Patient Participation , Surveys and QuestionnairesABSTRACT
Turner syndrome is recognized now as a syndrome familiar not only to pediatricians and pediatric specialists, medical geneticists, adult endocrinologists, and cardiologists, but also increasingly to primary care providers, internal medicine specialists, obstetricians, and reproductive medicine specialists. In addition, the care of women with Turner syndrome may involve social services, and various educational and neuropsychologic therapies. This article focuses on the recognition and management of Turner syndrome from adolescents in transition, through adulthood, and into another transition as older women. It can be viewed as an interpretation of recent international guidelines, complementary to those recommendations, and in some instances, an update. An attempt was made to provide an international perspective. Finally, the women and families who live with Turner syndrome and who inspired several sections, are themselves part of the broad readership that may benefit from this review.
Subject(s)
Turner Syndrome/diagnosis , Turner Syndrome/therapy , Adolescent , Adult , Aged , Child , Chromosomes, Human, Y/genetics , Humans , Karyotype , Mental Health , Middle Aged , Phenotype , Turner Syndrome/epidemiology , Turner Syndrome/genetics , Young AdultABSTRACT
Neurofibromatosis type 1 (NF1) is one of the most frequent genetic disorders, affecting 1:3,000 worldwide. Identification of genotype-phenotype correlations is challenging because of the wide range clinical variability, the progressive nature of the disorder, and extreme diversity of the mutational spectrum. We report 136 individuals with a distinct phenotype carrying one of five different NF1 missense mutations affecting p.Arg1809. Patients presented with multiple café-au-lait macules (CALM) with or without freckling and Lisch nodules, but no externally visible plexiform neurofibromas or clear cutaneous neurofibromas were found. About 25% of the individuals had Noonan-like features. Pulmonic stenosis and short stature were significantly more prevalent compared with classic cohorts (P < 0.0001). Developmental delays and/or learning disabilities were reported in over 50% of patients. Melanocytes cultured from a CALM in a segmental NF1-patient showed two different somatic NF1 mutations, p.Arg1809Cys and a multi-exon deletion, providing genetic evidence that p.Arg1809Cys is a loss-of-function mutation in the melanocytes and causes a pigmentary phenotype. Constitutional missense mutations at p.Arg1809 affect 1.23% of unrelated NF1 probands in the UAB cohort, therefore this specific NF1 genotype-phenotype correlation will affect counseling and management of a significant number of patients.
Subject(s)
Amino Acid Substitution , Codon , Mutation, Missense , Neurofibromin 1/genetics , Noonan Syndrome/diagnosis , Noonan Syndrome/genetics , Phenotype , Adolescent , Adult , Child , Child, Preschool , Cohort Studies , Dwarfism/genetics , Female , Genetic Association Studies , Humans , Infant , Male , Middle Aged , Neurofibromin 1/chemistry , Young AdultSubject(s)
Biological Specimen Banks , Turner Syndrome , Adult , Chromosomes, Human, X , Humans , Mosaicism , PenetranceABSTRACT
PURA syndrome is a rare, clinically heterogeneous disorder characterized by a wide spectrum of neurodevelopmental problems, and occasionally congenital heart defects, urogenital malformations, skeletal abnormalities and endocrine disorders. We describe the hospital course, diagnostic evaluations as well as neurologic and neuromuscular follow up of an infant diagnosed with PURA syndrome based on a pathogenic deletion at c.697_699 (p.Phe233del) of the PURA gene identified on whole exome sequencing. Upon initial examination, fluctuation of neuromuscular tone and reflexes were noted in conjunction with hypotonia and severe apneic episodes, suggestive of neuromuscular junction involvement. A definitive role of the neuromuscular junction has not been previously reported with PURA syndrome. The infant was started on pyridostigmine, an acetylcholinesterase inhibitor, with significant improvement in neuromuscular tone and motor movements. In addition, pyridostigmine also resulted in resolution of apneas and improved respiratory status which suggests its potential therapeutic role in patients with PURA syndrome.
Subject(s)
Channelopathies , Epilepsy , Intellectual Disability , Acetylcholinesterase/genetics , Apnea , DNA-Binding Proteins/genetics , Epilepsy/genetics , Humans , Infant , Intellectual Disability/genetics , Pyridostigmine Bromide/therapeutic use , Transcription Factors/geneticsABSTRACT
We present a patient with Phelan-McDermid syndrome, a rare neurodevelopmental disorder caused by a 22q13 deletion, with the previously undescribed finding of progressive dilation of the great arteries. While congenital heart defects have been identified in patients previously, dilation of the great arteries has not been described to our knowledge.
Subject(s)
DNA-Binding Proteins , Epilepsy , Humans , Transcription Factors , Neuromuscular Junction , Pyridostigmine BromideSubject(s)
Bone Marrow/metabolism , Brain Neoplasms/genetics , Colorectal Neoplasms/genetics , Neoplastic Syndromes, Hereditary/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Antibodies, Bispecific/administration & dosage , Antibodies, Bispecific/therapeutic use , Antineoplastic Agents, Immunological/administration & dosage , Antineoplastic Agents, Immunological/therapeutic use , Bone Marrow/abnormalities , Bone Marrow/pathology , Brain Neoplasms/complications , Child , Colorectal Neoplasms/complications , Fatal Outcome , Humans , Inotuzumab Ozogamicin/administration & dosage , Inotuzumab Ozogamicin/therapeutic use , Male , Mutation/genetics , Neoplastic Syndromes, Hereditary/complications , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/etiology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathologyABSTRACT
OBJECTIVES: Bicuspid aortic valve is the most common congenital cardiac abnormality, occurring in 1% to 2% of the population, and often associates with ascending aortic aneurysm. Based on familial studies, bicuspid aortic valve with aneurysm segregates in an autosomal dominant manner with incomplete penetrance. NOTCH1 mutations have been reported in 6 families with prominent valve calcification and dysfunction and low penetrance of aneurysm. We sought to determine the contribution of NOTCH1 mutations to the more common phenotype of highly penetrant aneurysms with low penetrance of bicuspid aortic valve and with rare valve calcification or dysfunction. METHODS: All exons and splice junctions of NOTCH1 were sequenced in probands from 13 affected families presenting with bicuspid aortic valve with ascending aortic aneurysm in the absence of valve calcification. In addition, mutation analysis was performed on a single individual with aneurysm and calcified tricuspid aortic valve. Sequences were aligned and compared with the reference genomic sequence. RESULTS: Corroborating previous studies, analysis of the single sporadic patient with calcified aortic valve in the presence of ascending aortic aneurysm revealed a novel heterozygous missense mutation in NOTCH1 resulting in a nonsynonymous amino acid substitution (p.T1090S, c.C3269G) of an evolutionarily conserved residue. This change was not observed in controls. In contrast, we did not identify any pathologic NOTCH1 mutations in the 13 families segregating noncalcified bicuspid aortic valve with highly penetrant aortic aneurysm. CONCLUSIONS: These data suggest that there are phenotypic differences that distinguish families with and without NOTCH1 mutations, indicating a genotype-phenotype correlation with potential implications for patient diagnosis, counseling, and management.
Subject(s)
Aortic Aneurysm/complications , Aortic Aneurysm/genetics , Genetic Association Studies , Mutation , Receptor, Notch1/genetics , Adolescent , Adult , Aortic Valve/abnormalities , Bicuspid Aortic Valve Disease , Child , Female , Heart Valve Diseases , Humans , Male , Pedigree , Young AdultABSTRACT
Oral-facial-digital syndrome type VI (OFD VI) is characterized by the association of malformations of the face, oral cavity and extremities, distinguished from the 12 other OFD syndromes by cerebellar and metacarpal abnormalities. Cerebellar malformations in OFD VI have been described as a molar tooth sign (MTS), thus, including OFD VI among the "Joubert syndrome related disorders" (JSRD). OFD VI diagnostic criteria have recently been suggested: MTS and one or more of the following: 1) tongue hamartoma(s) and/or additional frenula and/or upper lip notch; 2) mesoaxial polydactyly of hands or feet; 3) hypothalamic hamartoma. In order to further delineate this rare entity, we present the neurological and radiological data of 6 additional OFD VI patients. All patients presented oral malformations, facial dysmorphism and distal abnormalities including frequent polydactyly (66%), as well as neurological symptoms with moderate to severe mental retardation. Contrary to historically reported patients, mesoaxial polydactyly did not appear to be a predominant clinical feature in OFD VI. Sequencing analyzes of the 14 genes implicated in JSRD up to 2011 revealed only an OFD1 frameshift mutation in one female OFD VI patient, strengthening the link between these two oral-facial-digital syndromes and JSRD.