A founder mutation in causing intrafamilial and interfamilial phenotypic variability in a cohort of 18 patients with carbonic anhydrase VA deficiency.

Carbonic anhydrase VA (CA-VA) deficiency is a rare cause of hyperammonemia caused by biallelic mutations in Most patients present with hyperammonemic encephalopathy in early infancy to early childhood, and patients usually have no further recurrence of hyperammonemia with a favorable outcome. This retrospective cohort study reports 18 patients with CA-VA deficiency caused by homozygosity for a founder mutation, c.59G>A p.

Biallelic variants in the synaptic vesicle glycoprotein 2 A are associated with epileptic encephalopathy.

Synaptic Vesicle Glycoprotein 2 A (SV2A) is a membrane protein of synaptic vesicles and the binding site of antiepileptic drug levetiracetam. Biallelic Arg383Gln is reported in a family with intractable epilepsy earlier. Here, we report on the second family with early onset drug resistant epilepsy.

Hypoketotic hypoglycemia without neuromuscular complications in patients with SLC25A32 deficiency.

Mitochondrial flavin adenine dinucleotide (FAD) transporter deficiencies are new entities recently reported to cause a neuro-myopathic phenotype. We report three patients from two unrelated families who presented primarily with hypoketotic hypoglycemia. They all had acylcarnitine profiles suggestive of multiple acyl-CoA dehydrogenase deficiency (MADD) with negative next-generation sequencing of electron-transfer flavoprotein genes (ETFA, ETFB, and ETFDH).

CNP deficiency causes severe hypomyelinating leukodystrophy in humans.

Myelin pathologies are an important cause of multifactorial, e.g., multiple sclerosis, and Mendelian, e.