Background: The aim of the study was to investigate the incidence and genotype-phenotype characteristics of UDP-galactose-4'-epimerase (GALE) deficiency in newborn screening of Chinese population.
Methods: Neonates were screened at the Newborn Screening Center of Zhejiang Province, China for GALE deficiency and their condition was confirmed by testing of the GALE gene and GALE enzyme. Clinical and laboratory follow-up data were recorded.
Results: A total of 350,023 of newborns were screened; of which, the condition of one female neonate was diagnosed with GALE deficiency, accounting for an incidence rate of approximately 1:350,000 in our sample. The patient with GALE deficiency clinically manifested slight increase in levels of blood galactose (122-251 mg/L), glutamyl endopeptidase (61 U/L), total bile acid (17 μmol/L), and lactic acid (1.8 mmol/L). The neonate was fed with lactose-free powdered milk and followed-up to 1 year. Re-examination showed that all biochemical indicators recovered to normal range, whereas physical and mental development appeared normal without cataract change. The genotype of GALE deficiency was identified as compound heterozygous mutations: c.505C>T (p.R169W) and c.452G>A (p.G151D). The latter was a novel mutation. The GALE enzyme value was 42% of control.
Conclusions: GALE deficiency is relatively rare in China. The genotype of compound heterozygous mutations at R169W and G151D clinically manifest as mild-type; it is recommended to limit galactose diet.