Novel EDA mutations cause X-linked hypohidrotic ectodermal dysplasia: the first study from Venezuela

Hypohidrotic/anhidrotic ectodermal dysplasia (HED) is a rare genetic disorder affecting ectodermal tissues mainly including hair, teeth, sweat glands, skin and nails. It exhibits X-linked (XLHED) as well as autosomal dominant or recessive modes of inheritance. In the first study conducted from Venezuela, we analyzed two XLHED cases exhibiting classical clinical symptoms and identified a novel hemizygous EDA deletion (c.111delG) in one and a novel missense likely pathogenic variant (p.Gly192Glu) in the other. The current study adds to the growing repertoire of disease-causing EDA mutations with important implications for genetic screening in the affected families

Clinical and Genetic Aspects of Phelan−McDermid Syndrome: An Interdisciplinary Approach to Management

Phelan–McDermid syndrome (PMS) is a rare, heterogeneous, and complex neurodevelopmental disorder. It is generally caused by a heterozygous microdeletion of contiguous genes located in the distal portion of the long arm of chromosome 22, including the SHANK3 gene. Sequence variants of SHANK3, including frameshift, nonsense mutations, small indels and splice site mutations also result in PMS. Furthermore, haploinsufficiency in SHANK3 has been suggested as the main cause of PMS. SHANK3 is also associated with intellectual disability, autism spectrum disorder and schizophrenia. The phenotype of PMS is variable, and lacks a distinctive phenotypic characteristic, so the clinical diagnosis should be confirmed by genetic analysis. PMS is a multi-system disorder, and clinical care must encompass various specialties and therapists. The role of risperidone, intranasal insulin, insulin growth factor 1, and oxytocin as potential therapeutic options in PMS will be discussed in this review. The diagnosis of PMS is important to provide an appropriate clinical evaluation, treatment, and genetic counseling