Maternal health outcomes in ornithine transcarbamylase deficiency: A comparative analysis of pregnancies in symptomatic and asymptomatic heterozygotes.

Introduction: Ornithine transcarbamylase deficiency (OTCD, MIM: 311250) is an X-linked disorder of ureagenesis caused by pathogenic variants in OTC (MIM: 300461). Due to varying X-inactivation patterns, female heterozygotes can range from asymptomatic to severe disease with recurrent hyperammonemia. There is a paucity of data regarding the safety of pregnancy in symptomatic versus asymptomatic OTC heterozygotes.

Severe central sleep apnea in a child with biallelic variants in .

Unlabelled: The sodium leak channel, nonselective (NALCN), is necessary for the proper function of the neurons that play an important role in the sleep-wake cycle and regulation of breathing patterns during wakefulness and sleep. We report a 38-month-old male with developmental delay, hypotonia, and severe central sleep apnea with periodic breathing requiring noninvasive ventilation during sleep, who was found to have novel biallelic pathogenic variants in . A review of the literature illustrates 17 additional children with biallelic variants in the gene.

Biallelic variants in SLC38A3 encoding a glutamine transporter cause epileptic encephalopathy.

The solute carrier (SLC) superfamily encompasses >400 transmembrane transporters involved in the exchange of amino acids, nutrients, ions, metals, neurotransmitters and metabolites across biological membranes. SLCs are highly expressed in the mammalian brain; defects in nearly 100 unique SLC-encoding genes (OMIM: https://www.omim.

Plasma lyso-sphingomyelin levels are positively associated with clinical severity in acid sphingomyelinase deficiency.

Introduction: A reliable biomarker is urgently needed in the diagnosis and management of acid sphingomyelinase deficiency (ASMD, also known as Niemann Pick A, A/B, and B). Lyso-sphingomyelin (LSM) has previously been proposed as a biomarker for this disease. However, existing studies have not investigated the relationship between LSM levels and clinical subtype or severity.

Established and Emerging Treatments for Patients with Inborn Errors of Metabolism.

Inborn errors of metabolism (IEMs) are inherited defects in a metabolic pathway resulting in clinical disease. The overall goal of therapy is to restore metabolic homeostasis while minimizing the deleterious effects of the interruption. Conventional treatments focus on decreasing substrate, providing product, and replacing deficient enzyme or cofactor.

Clinical Manifestations of Noonan Syndrome and Related Disorders.

Noonan syndrome represents a heterogeneous group of genetic disorders caused by mutations in genes of the RAS/MAPK pathway. Related syndromes include cardiofaciocutaneous syndrome, Noonan syndrome with multiple lentigines and Costello syndrome. The common phenotypic features of Noonan syndrome include facial dysmorphisms, short stature, congenital heart defects and genitourinary abnormalities.