RESUMO
The cytochrome c-oxidase (COX) enzyme, also known as mitochondrial complex IV (MT-C4D), is a transmembrane protein complex found in mitochondria. COX deficiency is one of the most frequent causes of electron transport chain defects in humans. Therefore, high energy demand organs and tissues are affected in patients with mutations in the COX15 gene, with variable phenotypic expressiveness. We describe the case of a male newborn with hypertrophic cardiomyopathy and serum and cerebrospinal fluid hyperlacticaemia, whose exome sequencing revealed two variants in a compound heterozygous state: c.232G > A; p.(Gly78Arg), classified as likely pathogenic, and c.452C > G; p.(Ser151Ter), as pathogenic; the former never previously described in the literature.
Assuntos
Cardiomiopatia Hipertrófica/genética , Deficiência de Citocromo-c Oxidase/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Encefalomiopatias Mitocondriais/genética , Cardiomiopatia Hipertrófica/patologia , Deficiência de Citocromo-c Oxidase/patologia , Heterozigoto , Humanos , Recém-Nascido , Masculino , Encefalomiopatias Mitocondriais/patologia , Mutação , FenótipoRESUMO
Kenny-Caffey syndrome (KCS) is a rare hereditary skeletal disorder involving hypoparathyroidism. The autosomal dominant form (KCS2), caused by heterozygous pathogenic variants in the FAM111A gene, is distinguished from the autosomal recessive form (KCS1) and Sanjad-Sakati syndrome (SSS), both caused by pathogenic variants in the tubulin folding cofactor E (TBCE) gene, by the absence of microcephaly and intellectual disability. We present a patient with KCS2 caused by a de novo pathogenic variant c.1706G>A (p.Arg569His) in FAM111A gene, presenting intellectual disability and microcephaly, which are considered to be typical signs of SSS. We suggest that KCS1, KCS2, and SSS may not represent mutually exclusive clinical entities, but possibly an overlapping spectrum.