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

On the third day of life, total serum calcium (Ca) and phosphorus (P) were within the normal ranges (9.5 mg/dL and 5.8 mg/dL, respectively), but alkaline phosphatase (ALP) and parathyroid hormone (PTH) were markedly elevated (663 IU/L and 1,076.1 pg/mL, respectively). The serum 25-hydroxyvitamin D (25OHD) level was slightly low (5.5 mg/mL), while the 1,25-dihydroxyvitmin D (1,25D) level was normal (25.9 pg/mL). The urinary Ca/creatinine (Cr) ratio was 0.10 (reference range, 0.03 to 0.9), and the urinary P/ Cr ratio was 1.25 (reference range, 0.39 to 5.6). The following serum parameters were normal in a maternal blood sample: total Ca (9.0 mg/dL), phosphate (4.1 mg/dL), ALP (125 IU/L), PTH (16 pg/mL), 25OHD (10.1 ng/mL), and 1,25D (11.0 pg/mL). A secundum atrial septal defect (2.8 mm), a small muscular ventricular septal defect (1.5 mm), and a patent ductus arteriosus (3.35 mm) were detected on an echocardiogram. Significant valve abnormalities were not found. Ophthalmologic examination did not reveal blue sclera or corneal clouding, but stromal hypoplasia of both irises was discovered.