Expanding the clinical spectrum of mitochondrial <scp>3‐hydroxy‐3‐methylglutaryl‐CoA</scp> synthase deficiency with Turkish cases harboring novel <scp><i>HMGCS2</i></scp> gene mutations and literature review
Mustafa Kılıç, Sevil Dorum, Ali Topak, Mutlu Uysal Yazıcı, Fatih Süheyl Ezgü, Turgay Coşkun
Abstract
Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (mHS) deficiency is a very rare autosomal recessive inborn error of ketone body synthesis and presents with hypoketotic hypoglycemia, metabolic acidosis, lethargy, encephalopathy, and hepatomegaly with fatty liver precipitated by catabolic stress. We report acute presentation of two patients from unrelated two families with novel homozygous c.862C>T and c.725-2A>C mutations, respectively, in HMGCS2 gene. Affected patients had severe hypoketotic hypoglycemia, lethargy, encephalopathy, severe metabolic and lactic acidosis and hepatomegaly after infections. Surprisingly, molecular screening of the second family showed more affected patients without clinical findings. These cases expand the clinic spectrum of this extremely rare disease.