Hereditary deafness and retinal dystrophy are each genetically heterogenous and clinically variable. Three small unrelated families segregating the combination of deafness and retinal dystrophy were studied by exome sequencing (ES). The proband of Family 1 was found to be compound heterozygous for NM_004525.
View Article and Find Full Text PDFUsher syndrome has been historically categorized into one of three classical types based on the patient phenotype. However, the vestibular phenotype does not infallibly predict which Usher genes are mutated. Conversely, the Usher syndrome genotype is not sufficient to reliably predict vestibular function.
View Article and Find Full Text PDFPregnant and breastfeeding women have been rendered therapeutic orphans as they have been historically excluded from clinical trials. Labelling for most approved drugs does not provide information about safety and efficacy during pregnancy. This lack of data is mainly due to ethico-legal challenges that have remained entrenched in the post-diethylstilbestrol and thalidomide era, and that have led to pregnancy being viewed in the clinical trial setting primarily through a pharmacovigilance lens.
View Article and Find Full Text PDFAlthough much progress is being made in understanding the molecular pathways in the placenta that are involved in the pathophysiology of pregnancy-related disorders, a significant gap exists in the utilization of this information for the development of new drug therapies to improve pregnancy outcome. On March 5-6, 2015, the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health sponsored a 2-day workshop titled Placental Origins of Adverse Pregnancy Outcomes: Potential Molecular Targets to begin to address this gap. Particular emphasis was given to the identification of important molecular pathways that could serve as drug targets and the advantages and disadvantages of targeting these particular pathways.
View Article and Find Full Text PDFObjective: Xeroderma pigmentosum (XP) is a rare autosomal recessive disease caused by mutations in DNA repair genes. Clinical manifestations of XP include mild to extreme sensitivity to ultraviolet radiation resulting in inflammation and neoplasia in sun-exposed areas of the skin, mucous membranes, and ocular surfaces. This report describes the ocular manifestations of XP in patients systematically evaluated in the Clinical Center at the National Institutes of Health.
View Article and Find Full Text PDFBackground: Recessive mutant alleles of MYO7A, USH1C, CDH23, and PCDH15 cause non-syndromic deafness or type 1 Usher syndrome (USH1) characterised by deafness, vestibular areflexia, and vision loss due to retinitis pigmentosa. For CDH23, encoding cadherin 23, non-syndromic DFNB12 deafness is associated primarily with missense mutations hypothesised to have residual function. In contrast, homozygous nonsense, frame shift, splice site, and some missense mutations of CDH23, all of which are presumably functional null alleles, cause USH1D.
View Article and Find Full Text PDFHermansky-Pudlak syndrome (HPS) is an autosomal recessive condition characterized by a bleeding diathesis and hypopigmentation of the skin, hair, and eyes. Some HPS patients develop other complications such as granulomatous colitis and/or fatal pulmonary fibrosis. Eight genes have been associated with this condition, resulting in subtypes HPS-1 through HPS-8.
View Article and Find Full Text PDFAlkaptonuria is a rare, autosomal recessive disorder of tyrosine degradation due to deficiency of the third enzyme in the catabolic pathway. As a result, homogentisic acid (HGA) accumulates and is excreted in gram quantities in the urine, which turns dark upon alkalization. The first symptoms, occurring in early adulthood, involve a painful, progressively debilitating arthritis of the spine and large joints.
View Article and Find Full Text PDFUsher syndrome (USH) is a clinically heterogeneous condition characterized by sensorineural hearing loss, progressive retinal degeneration, and vestibular dysfunction. A minimum test battery is described as well as additional clinical evaluations that would provide comprehensive testing of hearing, vestibular function, and visual function in USH patients. USH is also genetically heterogeneous.
View Article and Find Full Text PDFAim: The aim of this study is to assess the role of Frizzled-4 (FZD4) in familial exudative vitreoretinopathy (FEVR) and Coats disease.
Methods: Tissue samples were collected for DNA extraction and automated DNA sequencing of the two coding exons of FZD4 in both directions. Cases carrying a FZD4 mutation and demonstrating extreme disease severity were selected for direct automated sequencing of all coding exons of LRP5, NDP and TSPAN12.
Chediak-Higashi syndrome (CHS) is a rare autosomal recessive disease characterized by variable oculocutaneous albinism, immunodeficiency, mild bleeding diathesis, and an accelerated lymphoproliferative state. Abnormal lysosome-related organelle membrane function leads to the accumulation of large intracellular vesicles in several cell types, including granulocytes, melanocytes, and platelets. This report describes a severe case of CHS resulting from paternal heterodisomy of chromosome 1, causing homozygosity for the most distal nonsense mutation (p.
View Article and Find Full Text PDFPurpose: The inherited bone marrow failure syndromes (IBMFS) are a heterogeneous group of genetic disorders that share the inability of the bone marrow to produce an adequate number of blood cells. The 4 most frequent syndromes are Fanconi anemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anemia (DBA), and Shwachman-Diamond syndrome (SDS). All 4 syndromes have been associated with various physical abnormalities.
View Article and Find Full Text PDFObjectives: To describe 3 children with mutations in a Meckel syndrome gene (MKS3), with features of autosomal recessive polycystic kidney disease (ARPKD), nephronophthisis, and Joubert syndrome (JS).
Study Design: Biochemical evaluations, magnetic resonance and ultrasound imaging, electroretinograms, IQ testing, and sequence analysis of the PKHD1 and MKS3 genes were performed. Functional consequences of the MKS3 mutations were evaluated by cDNA sequencing and transfection studies with constructs of meckelin, the protein product of MKS3.
Neurofibromatosis type 2 is an autosomal-dominant multiple neoplasia syndrome that results from mutations in the NF2 tumour suppressor gene located on chromosome 22q. It has a frequency of one in 25,000 livebirths and nearly 100% penetrance by 60 years of age. Half of patients inherit a germline mutation from an affected parent and the remainder acquire a de novo mutation for neurofibromatosis type 2.
View Article and Find Full Text PDFPediatr Blood Cancer
September 2009
Dyskeratosis congenita (DC) is a heterogeneous inherited bone marrow failure syndrome, characterized by abnormally short telomeres and mutations in telomere biology genes. The spectrum of telomere biology disorders is growing and the clinical management of these patients is complex. A DC-specific workshop was held at the NIH on September 19, 2008; participants included physicians, patients with DC, their family members, and representatives from other support groups.
View Article and Find Full Text PDFHermansky-Pudlak syndrome (HPS) develops from defects in the biogenesis and/or function of lysosome-related organelles essential to membrane and protein trafficking. Of the eight known human subtypes, only HPS-1 and HPS-4 develop pulmonary fibrosis in addition to the general clinical manifestations of oculocutaneous albinism and bleeding diathesis. We identified HPS-1 in three unrelated patients from different regions of India, who presented with iris transillumination, pale fundi, hypopigmentation, nystagmus, decreased visual acuity, and a bleeding diathesis.
View Article and Find Full Text PDFRecessive mutations of MYO7A, encoding unconventional myosin VIIA, can cause either a deaf-blindness syndrome (type 1 Usher syndrome; USH1B) or nonsyndromic deafness (DFNB2). In our study, deafness segregating as a recessive trait in 24 consanguineous families showed linkage to markers for the DFNB2/USH1B locus on chromosome 11q13.5.
View Article and Find Full Text PDFPurpose: To report variations in the inheritance pattern and clinical presentation of crystalline retinopathies.
Methods: Two different families with crystalline retinopathy were studied with a complete family history and ophthalmologic examination including Goldmann kinetic perimetry and electroretinography. Genetic studies were performed in one of the families.
Cystinosis is a rare autosomal recessive metabolic disorder characterized by the intracellular accumulation of cystine, the disulfide of the amino acid cysteine, in many organs and tissues. Infantile nephropathic cystinosis is the most severe phenotype. Corneal crystal accumulation and pigmentary retinopathy were originally the most commonly described ophthalmic manifestations, but successful kidney transplantation significantly changed the natural history of the disease.
View Article and Find Full Text PDFPurpose: Cystinosis is a rare autosomal recessive lysosomal storage disorder characterized by the intracellular accumulation of cystine. Treatment involves intracellular cystine depletion with oral cysteamine. A wide spectrum of ocular pathologic features has been associated with nephropathic cystinosis.
View Article and Find Full Text PDFA patient with osteogenesis imperfecta (OI) and some features of Ehlers-Danlos syndrome had Rieger's anomaly and other associated ocular abnormalities. He carried a COL1A1 mutation (c.3313delA) that has only rarely been seen in OI.
View Article and Find Full Text PDFThe purpose of this study was to establish diagnostic criteria for Stickler syndrome. Ninety patients from 38 families had complete evaluations for possible Stickler syndrome. Molecular confirmation of COL2A1 mutation status (type I Stickler syndrome) was available on 25 patients from six families.
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