MYH2-associated myopathy caused by a novel splice-site variant.

MYH2 encodes MyHCIIa, a myosin heavy chain found in fast type 2A fibers. Pathogenic variants in this gene have previously been implicated in dominant and recessive forms of myopathy. Three individuals reported here are part of a family in which four generations of individuals are affected by a slowly progressive, predominantly proximal myopathy in an autosomal dominant inheritance pattern.

A de novo hexokinase 1 (HK1) variant presenting as Boucher-Neuhäuser syndrome.

Boucher-Neuhäuser syndrome (BNHS) is characterized by chorioretinal dystrophy, hypogonadotropic hypogonadism, and cerebellar dysfunction and atrophy. The disorder has been associated with biallelic pathogenic variants in the patatin-like phospholipase domain-containing protein 6 (PNPLA6) gene. We present an individual with a clinical diagnosis consistent with BNHS who lacked any PNPLA6 variants but on quartet family exome sequencing had a de novo variant in the hexokinase 1 (HK1) gene (NM_000188.

Biallelic variants in two complex I genes cause abnormal splicing defects in probands with mild Leigh syndrome.

Leigh syndrome is a genetically heterogeneous disorder resulting from deficient oxidative energy biogenesis. The syndrome is characterized by subacute episodic decompensations, transiently elevated lactate, and necrotizing brain lesions most often in the striatum and brainstem. Acute decompensation is often triggered by viral infections.

Neurodegeneration as the presenting symptom in 2 adults with xeroderma pigmentosum complementation group F.

Objective: To describe the features of 2 unrelated adults with xeroderma pigmentosum complementation group F (XP-F) ascertained in a neurology care setting.

Methods: We report the clinical, imaging, molecular, and nucleotide excision repair (NER) capacity of 2 middle-aged women with progressive neurodegeneration ultimately diagnosed with XP-F.

Results: Both patients presented with adult-onset progressive neurologic deterioration involving chorea, ataxia, hearing loss, cognitive deficits, profound brain atrophy, and a history of skin photosensitivity, skin freckling, and/or skin neoplasms.

Late diagnosis and atypical brain imaging of Aicardi-Goutières syndrome: are we failing to diagnose Aicardi-Goutières syndrome-2?

Unlabelled: Aicardi-Goutières syndrome (AGS) is a rare disorder with in utero or postnatal onset of encephalopathy and progressive neurological deterioration. The seven genetic subtypes of AGS are associated with abnormal type I interferon-mediated innate immune response. Most patients with AGS present with progressive microcephaly, spasticity, and cognitive impairment.

Defining Disease, Diagnosis, and Translational Medicine within a Homeostatic Perturbation Paradigm: The National Institutes of Health Undiagnosed Diseases Program Experience.

Traditionally, the use of genomic information for personalized medical decisions relies on prior discovery and validation of genotype-phenotype associations. This approach constrains care for patients presenting with undescribed problems. The National Institutes of Health (NIH) Undiagnosed Diseases Program (UDP) hypothesized that defining disease as maladaptation to an ecological niche allows delineation of a logical framework to diagnose and evaluate such patients.

Computational evaluation of exome sequence data using human and model organism phenotypes improves diagnostic efficiency.

Purpose: Medical diagnosis and molecular or biochemical confirmation typically rely on the knowledge of the clinician. Although this is very difficult in extremely rare diseases, we hypothesized that the recording of patient phenotypes in Human Phenotype Ontology (HPO) terms and computationally ranking putative disease-associated sequence variants improves diagnosis, particularly for patients with atypical clinical profiles.

Methods: Using simulated exomes and the National Institutes of Health Undiagnosed Diseases Program (UDP) patient cohort and associated exome sequence, we tested our hypothesis using Exomiser.

The implications of familial incidental findings from exome sequencing: the NIH Undiagnosed Diseases Program experience.

Purpose: Using exome sequence data from 159 families participating in the National Institutes of Health Undiagnosed Diseases Program, we evaluated the number and inheritance mode of reportable incidental sequence variants.

Methods: Following the American College of Medical Genetics and Genomics recommendations for reporting of incidental findings from next-generation sequencing, we extracted variants in 56 genes from the exome sequence data of 543 subjects and determined the reportable incidental findings for each participant. We also defined variant status as inherited or de novo for those with available parental sequence data.

Neurotransmitter abnormalities and response to supplementation in SPG11.

Objective: To report the detection of secondary neurotransmitter abnormalities in a group of SPG11 patients and describe treatment with l-dopa/carbidopa and sapropterin.

Design: Case reports.

Setting: National Institutes of Health in the Undiagnosed Disease Program; Children's National Medical Center in the Myelin Disorders Bioregistry Program.

The National Institutes of Health Undiagnosed Diseases Program: insights into rare diseases.

Purpose: This report describes the National Institutes of Health Undiagnosed Diseases Program, details the Program's application of genomic technology to establish diagnoses, and details the Program's success rate during its first 2 years.

Methods: Each accepted study participant was extensively phenotyped. A subset of participants and selected family members (29 patients and 78 unaffected family members) was subjected to an integrated set of genomic analyses including high-density single-nucleotide polymorphism arrays and whole exome or genome analysis.