HCN2-Associated Neurodevelopmental Disorders: Data from Patients and Xenopus Cell Models.

Objective: We aimed to characterize the phenotypic spectrum and functional consequences associated with variants in HCN2, encoding for the hyperpolarization-activated cyclic nucleotide (HCN) gated channel 2.

Methods: GeneMatcher facilitated the recruitment of 21 individuals with HCN2 variants from 15 unrelated families, carrying HCN2 variants. In vitro functional studies were performed by electrophysiology with Xenopus laevis oocytes and membrane trafficking was investigated in HEK cells by confocal imaging.

RICTOR variants are associated with neurodevelopmental disorders.

RICTOR is a key component of the mTORC2 signaling complex which is involved in the regulation of cell growth, proliferation and survival. RICTOR is highly expressed in neurons and is necessary for brain development. Here, we report eight unrelated patients presenting with intellectual disability and/or development delay and carrying variants in the RICTOR gene.

DHDDS and NUS1: A Converging Pathway and Common Phenotype.

Background: Variants in dehydrodolichol diphosphate synthetase (DHDDS) and nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) cause a neurodevelopmental disorder, classically with prominent epilepsy. Recent reports suggest a complex movement disorder and an overlapping phenotype has been postulated due to their combined role in dolichol synthesis.

Cases: We describe three patients with heterozygous variants in DHDDS and five with variants affecting NUS1.

Biallelic loss-of-function variants in RABGAP1 cause a novel neurodevelopmental syndrome.

Purpose: RABGAP1 is a GTPase-activating protein implicated in a variety of cellular and molecular processes, including mitosis, cell migration, vesicular trafficking, and mTOR signaling. There are no known Mendelian diseases caused by variants in RABGAP1.

Methods: Through GeneMatcher, we identified 5 patients from 3 unrelated families with homozygous variants in the RABGAP1 gene found on exome sequencing.

PPA2-associated sudden cardiac death: extending the clinical and allelic spectrum in 20 new families.

Purpose: Biallelic hypomorphic variants in PPA2, encoding the mitochondrial inorganic pyrophosphatase 2 protein, have been recently identified in individuals presenting with sudden cardiac death, occasionally triggered by alcohol intake or a viral infection. Here we report 20 new families harboring PPA2 variants.

Methods: Synthesis of clinical and molecular data concerning 34 individuals harboring five previously reported PPA2 variants and 12 novel variants, 11 of which were functionally characterized.

Liver transplantation in children with inborn errors of metabolism: 30 years experience in NSW, Australia.

Background: Inborn errors of metabolism (IEM) are a diverse group of genetic disorders that can result in significant morbidity and sometimes death. Metabolic management can be challenging and burdensome for families. Liver transplantation (LT) is increasingly being considered a treatment option for some IEMs.

Short-acting erythropoiesis-stimulating agents for anaemia in predialysis patients.

Background: The benefits of erythropoiesis-stimulating agents (ESA) for chronic kidney disease (CKD) patients have been previously demonstrated. However, the efficacy and safety of short-acting epoetins administered at larger doses and reduced frequency as well as of new epoetins and biosimilars remains uncertain.

Objectives: This review aimed to evaluate the benefits and harms of different routes, frequencies and doses of epoetins (epoetin alpha, epoetin beta and other short-acting epoetins) for anaemia in adults and children with CKD not receiving dialysis.