MEGDHEL syndrome caused by SERAC1 gene variation: a case report and literature review / 中华围产医学杂志

ABSTRACT

Objective:To investigate the clinical and genetic features of 3-methylglutaconic aciduria, dystonia-deafness, hepatopathy, encephalopathy, Leigh-like syndrome(MEGDHEL syndrome) caused by SERAC1 gene variation. Methods:This study retrospectively described the clinical and molecular features and prognosis of a baby boy who was transferred to Children's Hospital of Fudan University and later diagnosed with MEGDHEL syndrome in August 2016. A summary of the clinical and genetic manifestations of MEGDHEL syndrome cases reported in China and foreign areas was conducted through a literature review.Results:(1) Case report The 2-day-old patient was transferred to Children's Hospital of Fudan University due to hyperlactic acidemia after birth. Physical examination revealed scattered petechiae and ecchymoses of the skin. Laboratory examination showed coagulation disorders and cranial MRI revealed abnormal signals in both basal ganglia. A homozygous variation of c.442C>T(p.Arg148*) in the SERAC1 gene was detected in the patient, which is a pathogenic variant included in the Human Gene Mutation Database. Both of his parents were heterozygous carriers, thereby the diagnosis of MEGDHEL syndrome was confirmed. Followed up to the age of three years and 11 months, he was found to have psychomotor retardation, spasticity, dystonia, deafness, and loss of language ability. (2)Literature review Together with the case reported in this study, a total of 88 cases were retrieved, involving 57 different variants. The clinical features were homogenous, with onset mostly in the neonatal period (72%, 62/86), and severe reversible liver dysfunction (49%, 38/77) and neonatal hypoglycemia (44%, 35/80) were the main features. Nervous system was affected since infancy and common symptoms, included hypotonia (86%, 68/79), progressive spasticity (82%, 67/82), dystonia (80%, 66/82), intellectual disability (88%, 58/66) and sensorineural hearing impairment (74%, 59/80). Furthermore, bilateral basal ganglia involvement on cranial MRI (93%,70/75) and 3-methylglutaconic aciduria (98%,80/82) were also seen. Supportive care is currently the main management, however, the prognosis is extremely poor. Conclusions:MEGDHEL syndrome should be highly suspected when reversible neonatal liver dysfunction or hypoglycemia of unknown reasons in neonatal period, followed by progressive deafness-dystonia syndrome in infancy. As the prognosis of these patients is usually poor, genetic testing may provide an early diagnosis in neonatal period.