OBJECTIVE@#To explore the clinical and genetic characteristics of a
child with MEGDEL
syndrome.@*
METHODS@#Clinical data of the
child was reviewed. Peripheral
blood samples of the
child and his
parents were collected.
Mitochondrial genome and the whole
exome of the
child were analyzed by
next-generation sequencing. Candidate variants and its origin were verified by Sanger sequencing and
fluorescence quantitative
PCR.@*RESULTS@#The
patient, a 2-year-and-6-month-old
male, has featured
hypoglycemia, mental and motor retardation with regression. Cranial MRI showed bilateral
putamen damage suggestive of
Leigh syndrome. Testing of
urine organic
acid indicated that the level of 3-methylpentenoic
acid was slightly increased.
Whole exome sequencing revealed that the
child has harbored heterozygous deletion of
exons 6 to 17 and c.307A>T nonsense variant of the SERAC1
gene, which were respectively inherited from his
parents who were asymptomatic.
Treatment with
Levocarnitine,
vitamin B1,
vitamin B2,
coenzyme Q10,
baclofen and glucuronolactone resulted in improvement of
sleep and mental
state.@*CONCLUSION@#A case of MEGDEL
syndrome without
deafness was diagnosed. Discovery of the
nonsense mutation and large fragment deletion have enriched the spectrum of SERAC1
gene variants.