Novel MYO5B Mutation in Microvillous Inclusion Disease of Syrian Ancestry

Microvillus inclusion disease (MVID, MIM♯ 251850), also known as congenital microvil-lus atrophy, was first described by Davidson et al. in 1978. It is a rare au-tosomal recessive disease that presents with an intractable life-threatening watery diarrhea either within the first days of life (early-onset form) or at several months of life (late-onset form) . The hallmarks of MVID are a lack of microvilli on the surface of villous enterocytes, occurrence of microvillous inclusions and the cytoplasmic accumulation of periodic acid-schiff-positive vesicles. In 2008, Muller et al showed that mutations in MYO5B (MIM ♯ 606540), en-coding the unconventional type Vb myosin motor protein, were associated with MVID in an ex-tended Turkish kindred. Since then, more mutations were described in different populations . In this report we describe a novel mutation in two unrelated Syrian patients with MVID.

NGS Gene Panel Analysis Revealed Novel Mutations in Patients with Rare Congenital Diarrheal Disorders

Congenital diarrheal disorders (CDDs) are early-onset enteropathies generally inherited as autosomal recessive traits. Most patients with CDDs require rapid diagnosis as they need immediate and specific therapy to avoid a poor prognosis, but their clinical picture is often overlapping with a myriad of nongenetic diarrheal diseases. We developed a next-generation sequencing (NGS) panel for the analysis of 92 CDD-related genes, by which we analyzed patients suspect for CDD, among which were (i) three patients with sucrose-isomaltase deficiency; (ii) four patients with microvillous inclusion disease; (iii) five patients with congenital tufting enteropathy; (iv) eight patients with glucose-galactose malabsorption; (v) five patients with congenital chloride diarrhea. In all cases, we identified the mutations in the disease-gene, among which were several novel mutations for which we defined pathogenicity using a combination of bioinformatic tools. Although CDDs are rare, all together, they have an incidence of about 1%. Considering that the clinical picture of these disorders is often confusing, a CDD-related multigene NGS panel contributes to unequivocal and rapid diagnosis, which also reduces the need for invasive procedures.