Korean J Pediatr.  2012 Nov;55(11):438-444. 10.3345/kjp.2012.55.11.438.

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

• Heo JS
• Choi KY
• Sohn SH
• Kim C
• Kim YJ
• Shin SH
• Lee JM
• Lee J
• Sohn JA
• Lim BC
• Lee JA
• Choi CW
• Kim EK
• Kim HS
• Kim BI
• Choi JH

• KMID: 1781706
• DOI: http://doi.org/10.3345/kjp.2012.55.11.438

Abstract

Mucolipidosis II (ML II) or inclusion cell disease (I-cell disease) is a rarely occurring autosomal recessive lysosomal enzyme-targeting disease. This disease is usually found to occur in individuals aged between 6 and 12 months, with a clinical phenotype resembling that of Hurler syndrome and radiological findings resembling those of dysostosis multiplex. However, we encountered a rare case of an infant with ML II who presented with prenatal skeletal dysplasia and typical clinical features of severe secondary hyperparathyroidism at birth. A female infant was born at 37(+1) weeks of gestation with a birth weight of 1,690 g (<3rd percentile). Prenatal ultrasonographic findings revealed intrauterine growth retardation and skeletal dysplasia. At birth, the patient had characteristic features of ML II, and skeletal radiographs revealed dysostosis multiplex, similar to rickets. In addition, the patient had high levels of alkaline phosphatase and parathyroid hormone, consistent with severe secondary neonatal hyperparathyroidism. The activities of beta-D-hexosaminidase and alpha-N-acetylglucosaminidase were moderately decreased in the leukocytes but were 5- to 10-fold higher in the plasma. Examination of a placental biopsy specimen showed foamy vacuolar changes in trophoblasts and syncytiotrophoblasts. The diagnosis of ML II was confirmed via GNPTAB genetic testing, which revealed compound heterozygosity of c.3091C>T (p.Arg1031X) and c.3456_3459dupCAAC (p.Ile1154GlnfsX3), the latter being a novel mutation. The infant was treated with vitamin D supplements but expired because of asphyxia at the age of 2 months.

Keyword

Mucolipidosis; Newborn infant; Secondary hyperparathyroidism; Enzyme assays; Human GNPTAB protein

MeSH Terms

Acetylglucosaminidase
Aged
Alkaline Phosphatase
Asphyxia
Biopsy
Birth Weight
Dysostoses
Enzyme Assays
Female
Fetal Growth Retardation
Genetic Testing
Humans
Hyperparathyroidism
Hyperparathyroidism, Secondary
Infant
Infant, Newborn
Leukocytes
Mucolipidoses
Mucopolysaccharidosis I
Parathyroid Hormone
Parturition
Phenotype
Plasma
Pregnancy
Rickets
Trophoblasts
Vitamin D
Acetylglucosaminidase
Alkaline Phosphatase
Parathyroid Hormone
Vitamin D