Usher syndrome with methylmalonic acidemia and homocysteine in an infant / 中华围产医学杂志

ABSTRACT

A case of Usher syndrome with methylmalonic acidemia and homocysteine is reported. The patient was a two-month-old and small for gestational age male infant hospitalized for "feeding difficulties" during the neonatal period. The baby boy presented hypotonia, microcephaly, and hearing loss after birth. Genetic test found compound heterozygous mutations of c.482G>A and c.567dup in MMACHC, and both were pathogenic mutations inherited from his parents. Moreover, the patient also had compound heterozygous variants at c.2802T>G and c.14017T>C of USH2A gene. The former was suspected to be pathogenic, and the latter was of unknown clinical significance. Both were from the parents. Usher syndrome and methylmalonic acidemia with homocysteine were clinically diagnosed. Followed up to the age of two, the child was found with moderate mental retardation, while the physical development was comparable to that of the same age group.