Congenital Titinopathy: Comprehensive Characterization of the Most Severe End of the Disease Spectrum.

Unlabelled: Congenital titinopathy has recently emerged as one of the most common congenital muscle disorders.

Objective: To better understand the presentation and clinical needs of the under-characterized extreme end of the congenital titinopathy severity spectrum.

Methods: We comprehensively analyzed the clinical, imaging, pathology, autopsy, and genetic findings in 15 severely affected individuals from 11 families.

Collagen IV deficiency causes hypertrophic remodeling and endothelium-dependent hyperpolarization in small vessel disease with intracerebral hemorrhage.

Background: Genetic variants in COL4A1 and COL4A2 (encoding collagen IV alpha chain 1/2) occur in genetic and sporadic forms of cerebral small vessel disease (CSVD), a leading cause of stroke, dementia and intracerebral haemorrhage (ICH). However, the molecular mechanisms of CSVD with ICH and COL4A1/COL4A2 variants remain obscure.

Methods: Vascular function and molecular investigations in mice with a Col4a1 missense mutation and heterozygous Col4a2 knock-out mice were combined with analysis of human brain endothelial cells harboring COL4A1/COL4A2 mutations, and brain tissue of patients with sporadic CSVD with ICH.

Hypothyroidism due to biallelic variants in IYD: description of 4 families and a novel variant.

Biallelic loss-of-function variants in the IYD gene cause hypothyroidism resulting from iodine wasting. We describe 8 patients (from 4 families in which the parents are first cousins) who are homozygous for a variant in IYD (including a novel missense deleterious variant, c.791C>T [P264L], in 1 family).

A milder form of NSRP1-associated neurodevelopmental disorder, caused by a missense variant in the nuclear localization signal.

Nuclear Speckle Splicing Regulator Protein 1 (NSRP1) is a splice factor found in nuclear speckles, which are small membrane-free organelles implicated in epigenetic regulation, chromatin organization, DNA repair, and RNA modification. Bi-allelic loss-of-function variants in NSRP1 have recently been identified in patients suffering from a severe neurodevelopmental disorder, presenting with neurodevelopmental delay, epilepsy, microcephaly, hypotonia, and spastic cerebral palsy. Described patients acquired neither independent walking nor speech and often showed anomalies on cerebral MRI.

Clinical and Molecular Spectrum of Autosomal Recessive CA8-Related Cerebellar Ataxia.

Background: Based on a limited number of reported families, biallelic CA8 variants have currently been associated with a recessive neurological disorder named, cerebellar ataxia, mental retardation, and dysequilibrium syndrome 3 (CAMRQ-3).

Objectives: We aim to comprehensively investigate CA8-related disorders (CA8-RD) by reviewing existing literature and exploring neurological, neuroradiological, and molecular observations in a cohort of newly identified patients.

Methods: We analyzed the phenotype of 27 affected individuals from 14 families with biallelic CA8 variants (including data from 15 newly identified patients from eight families), ages 4 to 35 years.