A case of mucolipidosis II presenting with prenatal skeletal dysplasia and severe secondary hyperparathyroidism at birth

Heo, Ju Sun; Choi, Ka Young; Sohn, Se Hyoung; Kim, Curie; Kim, Yoon Joo; Shin, Seung Han; Lee, Jae Myung; Lee, Juyoung; Sohn, Jin A; Lim, Byung Chan; Lee, Jin A; Choi, Chang Won; Kim, Ee-Kyung; Kim, Han-Suk; Kim, Beyong Il; Choi, Jung-Hwan

ML II is an autosomal recessive lysosomal enzyme-targeting disease. Although the true prevalence of ML II is unknown, the disease appears to be rare. Its prevalence has been estimated at 1/123,500 live births in Portugal 23) , 1/252,500 in Japan 16) , and 1/625,500 in the Netherlands 24) . In Korea, there are very few reports of mucolipidosis [25] [26] [27] . There were 3 cases of ML II, 3 cases of ML III, and 1 case of ML that was not classified. All cases of ML II were diagnosed after one year of age (1.4 to 2.3 years) and they had typical characteristics of ML II, such as growth retardation, developmental delay, and severe skeletal deformity. Unlike these cases, our case exhibited skeletal dysplasia and intrauterine growth retardation before 30 weeks of gestation. The characteristic clinical phenotype, the radiological feature of dysostosis multiplex resembling rickets, and severe osteopenia were present at birth. Our patient was diagnosed with ML II during the neonatal period. To the best of our knowledge, this is the first case of ML II that manifested during the prenatal period and diagnosed neonatally in Korea.