The proband is a 4-month-old male infant, the second affected child of healthy non-consanguineous parents. His elder brother experienced similar symptoms and died 5 years ago at the age of 4 months. The proband was born at term with a birth weight of 2.53 kg following a normal pregnancy. On the second day after birth, the patient presented with frequent apneas and cyanosis, and was transferred to our hospital.
He presented with hypotonia and marked muscle weakness. His blood oxygen level was reduced to 77% (normal range for newborns: 93-100%), and the heart rate dropped to 110-120 beats/min (normal range for newborns:120-140 beats/min). The peripheral blood glucose fluctuated between 4.0 and 6.0 mmol/L (normal range: 3.9-6.1 mmol/L) during this period. Nasal continuous positive airway pressure (NCPAP) was used to maintain airway patency. A CT scan of the brain revealed an existing subarachnoid hemorrhage. Laboratory investigations revealed plasma lactate concentration fluctuated between normal and abnormal. Blood acylcarnitine analysis and urinary organic acid profiling showed no abnormality. Laboratory tests revealed total bilirubin (TBIL) of 170.8 mumol/L (normal range: 0-23 mumol/L) and direct bilirubin (DBIL) of 11.1 mumol/L (normal range: 0-4 mumol/L), and renal functions were basically normal.
After being hospitalized for 5 days in our hospital, the child was transferred to a provincial hospital for more than 2 months. During this period, the child underwent a number of examinations and no clear cause was determined. At said hospital, no pathogenic mutations or copy number variations were found in genes related to the disease.