Full-length Isoform Sequencing for Resolving the Molecular Basis of Charcot-Marie-Tooth 2A.

Objectives: Transcript sequencing of patient-derived samples has been shown to improve the diagnostic yield for solving cases of suspected Mendelian conditions, yet the added benefit of full-length long-read transcript sequencing is largely unexplored.

Methods: We applied short-read and full-length transcript sequencing and mitochondrial functional studies to a patient-derived fibroblast cell line from an individual with neuropathy that previously lacked a molecular diagnosis.

Results: We identified an intronic homozygous c.

Dominant-negative variant in SLC1A4 causes an autosomal dominant epilepsy syndrome.

SLC1A4 is a trimeric neutral amino acid transporter essential for shuttling L-serine from astrocytes into neurons. Individuals with biallelic variants in SLC1A4 are known to have spastic tetraplegia, thin corpus callosum, and progressive microcephaly (SPATCCM) syndrome, but individuals with heterozygous variants are not thought to have disease. We identify an 8-year-old patient with global developmental delay, spasticity, epilepsy, and microcephaly who has a de novo heterozygous three amino acid duplication in SLC1A4 (L86_M88dup).

Full-length isoform sequencing for resolving the molecular basis of Charcot-Marie-Tooth 2A.

Objectives: Transcript sequencing of patient derived samples has been shown to improve the diagnostic yield for solving cases of likely Mendelian disorders, yet the added benefit of full-length long-read transcript sequencing is largely unexplored.

Methods: We applied short-read and full-length isoform cDNA sequencing and mitochondrial functional studies to a patient-derived fibroblast cell line from an individual with neuropathy that previously lacked a molecular diagnosis.

Results: We identified an intronic homozygous c.

Cardiovascular outcomes of pregnancy in Turner syndrome.

Objectives: Women with Turner syndrome (TS) are frequently counselled against pregnancy due to lack of data and unclear aortic dissection risk. However, with advances in fertility therapy, more women with TS are contemplating pregnancy. This study compared rates of adverse cardiovascular (CV) outcomes among: (1) pregnant and non-pregnant women with TS and (2) pregnant women with TS with/without structural heart disease.

Ectodermal dysplasias: Classification and organization by phenotype, genotype and molecular pathway.

An international advisory group met at the National Institutes of Health in Bethesda, Maryland in 2017, to discuss a new classification system for the ectodermal dysplasias (EDs) that would integrate both clinical and molecular information. We propose the following, a working definition of the EDs building on previous classification systems and incorporating current approaches to diagnosis: EDs are genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. Genetic variations in genes known to be associated with EDs that affect only one derivative of the ectoderm (attenuated phenotype) will be grouped as non-syndromic traits of the causative gene (e.

Postnatal outcomes of prenatally diagnosed 45,X/46,XX.

High quality information is critical for informed decision-making in pregnancy following a prenatal diagnosis of sex chromosome aneuploidy. The goal of this study was to define the spectrum of outcomes in patients with prenatally diagnosed 45,X/46,XX mosaic Turner syndrome in order to provide a better basis for genetic counseling at the time of intrauterine diagnosis. Phenotype data for twenty-five patients with prenatally diagnosed 45,X/46,XX mosaicism were collected by retrospective chart review and, when possible, semi-structured telephone interview.

A Point Mutation in PDGFRB Causes Autosomal-Dominant Penttinen Syndrome.

Penttinen syndrome is a distinctive disorder characterized by a prematurely aged appearance with lipoatrophy, epidermal and dermal atrophy along with hypertrophic lesions that resemble scars, thin hair, proptosis, underdeveloped cheekbones, and marked acro-osteolysis. All individuals have been simplex cases. Exome sequencing of an affected individual identified a de novo c.

Actionable exomic incidental findings in 6503 participants: challenges of variant classification.

Recommendations for laboratories to report incidental findings from genomic tests have stimulated interest in such results. In order to investigate the criteria and processes for assigning the pathogenicity of specific variants and to estimate the frequency of such incidental findings in patients of European and African ancestry, we classified potentially actionable pathogenic single-nucleotide variants (SNVs) in all 4300 European- and 2203 African-ancestry participants sequenced by the NHLBI Exome Sequencing Project (ESP). We considered 112 gene-disease pairs selected by an expert panel as associated with medically actionable genetic disorders that may be undiagnosed in adults.

Ventral midline blanching in the setting of segmental infantile hemangiomas: clinical observations and pathogenetic implications.

Areas of blanched skin in children may be seen as an independent finding or in association with vascular birthmarks. We performed a retrospective chart review to identify and describe infants with areas of ventral midline blanching in the presence of segmental infantile hemangiomas. We identified nine full-term infants with partial or full segmental hemangiomas and areas of midline ventral blanching.

Folliculocystic and collagen hamartoma of tuberous sclerosis complex.

Background: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by tumors and hamartomas in several organs including the skin.

Objective: We sought to describe a new type of complex hamartoma in patients with TSC.

Methods: This was a retrospective clinical and histopathologic evaluation of 6 cases.

Keratosis Follicularis Spinulosa Decalvans is caused by mutations in MBTPS2.

Keratosis Follicularis Spinulosa Decalvans (KFSD) is a rare genetic disorder characterized by development of hyperkeratotic follicular papules on the scalp followed by progressive alopecia of the scalp, eyelashes, and eyebrows. Associated eye findings include photophobia in childhood and corneal dystrophy. Due to the genetic and clinical heterogeneity of similar disorders, a definitive diagnosis of KFSD is often challenging.

Genetic counseling in epidermolysis bullosa.

This article contains the author's views on genetic counseling in cases concerning the epidermolysis bullosa syndromes. The provision of genetic counseling entails absolutes such as diagnosis, natural history, treatment, mode of inheritance, recurrence risks/prenatal diagnosis and referral. The genetic counselor needs to be informed and informative and answer all the needs of the patients and their families reliably both at the initial consultation and subsequently as needed over the course of the patient's life.

Dermatologic findings of ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome.

Hay-Wells syndrome, caused by mutations in the p63 gene, is an autosomal dominant ectodermal dysplasia with the main features of ankyloblepharon filiforme adnatum, ectodermal defects, and cleft lip/palate, from which the disorder's other name, AEC syndrome, is derived. The National Foundation for Ectodermal Dysplasias convened the International Research Symposium for AEC Syndrome on November 8-10, 2006, at Texas Children's Hospital/Baylor College of Medicine, Houston, TX with appropriate IRB approval. This multidisciplinary conference was the largest gathering of such patients to date and allowed us to further characterize dermatologic features of AEC syndrome, which included: sparse and wiry hair, nail changes, past or present scalp erosions, decreased sweat production, palmar/plantar changes, and unique pigmentary anomalies.

International Research Symposium on Ankyloblepharon-Ectodermal Defects-Cleft Lip/Palate (AEC) syndrome.

Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome (Hay-Wells syndrome, MIM #106220) is a rare autosomal dominant ectodermal dysplasia syndrome. It is due to mutations in the TP63 gene, known to be a regulatory gene with many downstream gene targets. TP63 is important in the differentiation and proliferation of the epidermis, as well as many other processes including limb and facial development.

Hereditary woolly hair and keratosis pilaris.

We describe a family with woolly hair and ulerythema ophryogenes spanning four generations. Both woolly hair and ulerythema ophryogenes have been associated with Noonan syndrome and cardiofaciocutaneous syndrome (CFC), two disorders with considerable phenotypic overlap. This family did not exhibit any of the other findings characteristic of either Noonan syndrome or CFC, similar to a previously described pedigree with hereditary woolly hair.

Growth characteristics of children with ectodermal dysplasia syndromes.

Objective: Clinical observations suggested that growth abnormalities may be present in children with ectodermal dysplasia (ED) syndromes. This study characterizes the longitudinal pattern of growth in a cohort of children with the ED syndromes. We hypothesized that (1) linear and ponderal growth abnormalities are present in children with ED from infancy through adolescence, and (2) linear and ponderal growth abnormalities differ among the clinical variants of these disorders.

Mosaicism in cutaneous pigmentation.

Purpose Of Review: This article reviews the disorders of patterned dyspigmentation and discusses the pathogenesis of the pigmentary changes.

Recent Findings: A range of cytogenetic abnormalities has been detected in patterned pigmentary disease. This molecular heterogeneity correlates with the wide spectrum of clinical phenotypes observed.

Metastatic malignant melanoma presenting as pancytopenia in a three-year-old boy.

Malignant melanoma is rare in childhood and has never been reported to cause pancytopenia due to bone marrow metastases in a child. We report a 3-year-old boy with a large congenital melanocytic nevus who presented with bone pain and pancytopenia due to diffuse bone and bone marrow infiltration with metastatic melanoma without an identifiable primary site. Despite treatment with imatinib mesylate there was no response and the patient died with progressive disease.

Mutations in ABCA12 underlie the severe congenital skin disease harlequin ichthyosis.

Harlequin ichthyosis (HI) is the most severe and frequently lethal form of recessive congenital ichthyosis. Although defects in lipid transport, protein phosphatase activity, and differentiation have been described, the genetic basis underlying the clinical and cellular phenotypes of HI has yet to be determined. By use of single-nucleotide-polymorphism chip technology and homozygosity mapping, a common region of homozygosity was observed in five patients with HI in the chromosomal region 2q35.