High frequency of MEFV disease-causing variants in children with very-early-onset inflammatory bowel disease.

Background: Biological similarities between inflammatory bowel disease (IBD) and familial Mediterranean fever (FMF) have been described in humans and animal models suggesting a possible common genetic basis. FMF is caused by variants in the MEFV gene which encodes pyrin, an immune regulator. This study aimed to investigate the carrier rate of disease-causing MEFV variants in children of different ethnicities diagnosed with very-early-onset IBD (VEO-IBD).

Loss of function of PCDH12 underlies recessive microcephaly mimicking intrauterine infection.

Objective: To identify the genetic basis of a recessive syndrome characterized by prenatal hyperechogenic brain foci, congenital microcephaly, hypothalamic midbrain dysplasia, epilepsy, and profound global developmental disability.

Methods: Identification of the responsible gene by whole exome sequencing and homozygosity mapping.

Results: Ten patients from 4 consanguineous Palestinian families manifested in utero with hyperechogenic brain foci, microcephaly, and intrauterine growth retardation.

Expanding the phenotype of CRB2 mutations - A new ciliopathy syndrome?

Recessive CRB2 mutations were recently reported to cause both steroid resistant nephrotic syndrome and prenatal onset ventriculomegaly with kidney disease. We report two Ashkenazi Jewish siblings clinically diagnosed with ciliopathy. Both presented with severe congenital hydrocephalus and mild urinary tract anomalies.

Spinal muscular atrophy with pontocerebellar hypoplasia is caused by a mutation in the VRK1 gene.

The spinal muscular atrophies (SMAs) are a genetically and clinically heterogeneous group of disorders characterized by degeneration and loss of anterior horn cells in the spinal cord, leading to muscle weakness and atrophy. Spinal muscular atrophy with pontocerebellar hypoplasia (SMA-PCH, also known as pontocerebellar hypoplasia type 1 [PCH1]) is one of the rare infantile SMA variants that include additional clinical manifestations, and its genetic basis is unknown. We used a homozygosity mapping and positional cloning approach in a consanguineous family of Ashkenazi Jewish origin and identified a nonsense mutation in the vaccinia-related kinase 1 gene (VRK1) as a cause of SMA-PCH.

Nasal potential difference in non-classic cystic fibrosis-long term follow up.

Background: Nasal potential difference (NPD) measurement is an electrophysiological test that assesses cystic fibrosis transmembrane conductance regulator (CFTR) activity and is a recognized diagnostic tool in CF. The aim of this study is to assess in the long term the role of NPD in patients whose diagnosis is questionable.

Methods: We performed follow up study on 70 patients with questionable CF (QCF) who were divided previously into two groups according to their NPD results: patients who likely have CF (QCF-CF) (n = 24), and those who likely do not have CF (QCF-non-CF) (n = 46).