Intrauterine growth acceleration in the case of a severe form of mucopolysaccharidosis type VII.

We describe a Japanese male infant with mucopoly-saccharidosis type VII (MPS VII) who was born at 32 weeks of gestation presenting as a non-immune hydrops fetalis. His birth weight was 2900 g (+4.1 SD), his birth length was 48 cm (+2.2 SD), and thoracic spine length was 9.5 cm (+2.7 SD) at birth. Ossification center was already discernible bilaterally in coracoid process and distal femur at birth. In eight newborn infants with fetal hydrops of various other etiologies born in our institution, birth length ranged from -0.2 to -1.5 SD and thoracic spine length ranged from +0.5 to -1.7 SD, and neither ossification center of coracoid process nor distal femur were visible. The above data indicate that hydrops fetalis form of MPS VII is associated with intrauterine growth acceleration accompanied by early bone maturation. This feature may be useful in differentiating MPS VII associated hydrops fetalis from those of other etiologies.