Two cases of neonatal hyperglycemia caused by a homozygous COQ9 stop-gain variant.

ABSTRACT: Neonatal diabetes mellitus (NDM) is a monogenic condition diagnosed <6 months of age with >40 genetic causes. International guidelines recommend referral for genetic testing immediately after diagnosis since the genetic result guides clinical management. We used next-generation sequencing to identify a homozygous pathogenic variant, p.(Arg244*), in COQ9 in 2 individuals referred for NDM testing. Both had insulin-treated hyperglycemia, severe structural brain defects, dysmorphic features, and lactic acidosis. Recessive loss-of-function variants in COQ9 cause Coenzyme Q10 deficiency-5, a multi-system mitochondrial disease, with 7 cases reported. Neonatal hyperglycemia has not been reported in any of these cases but has been described for two other Coenzyme Q10 disorders caused by variants in

SUBMITTER: Donis R 

PROVIDER: S-EPMC12057368 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature