Lethal mitochondrial trifunctional protein deficiency caused by HADHB gene variation: a case report / 中华围产医学杂志

ABSTRACT

This article reported a male neonate with lethal mitochondrial trifunctional protein deficiency (MTPD) caused by compound heterozygous variations in the HADHB gene. The patient presented with poor milk intake complicated by abnormal myocardial enzymes within 24 h after birth and was transferred to the Children's Hospital of Nanjing Medical University on day 4. Physical examination revealed no obvious abnormalities on admission. Laboratory examination showed increased creatine kinase isoenzyme and cardiac troponin levels, and electrocardiogram suggested sinus tachycardia and low QRS voltage in limb leads. Blood screening for metabolic abnormalities showed high levels of tetradecenyl carnitine and various 3-hydroxycarnitines. Heterozygous mutations of c.739C>T(p.Arg247Cys) and c.607C>T(p.Arg203Ter,272) were detected in the HADHB gene in the boy, which were pathogenic variants included in the Human Gene Mutation Database. Followed up to three months of age, the boy was readmitted to hospital due to poor milk intake for one week and poor response for 2 d after catching a cold. After admission, he quickly developed multiple organs dysfunction such as heart failure and respiratory failure, and then died. Lethal MTPD is rare with no effective treatment and poor prognosis. Lethal MTPD should be highly suspected when unexplained cardiomyopathy, hypoglycemia, acidosis and other metabolic abnormalities appear in the neonatal period, and an early diagnosis could be confirmed with genetic testing in the neonatal period.