A case of I-cell disease (mucolipidosis II) presenting with short femurs on prenatal ultrasound and profound diaphyseal cloaking

A 28-year-old G3 P1 SAB1 female with no prior health concerns was found to have a foetus with short femurs on prenatal ultrasound following an abnormal maternal serum screen result. Fluid obtained by amniocentesis revealed an elevated α-fetoprotein level with absence of an acetylcholinesterase band and normal male karyotype (46,XY). Follow-up ultrasound 3 weeks later again demonstrated short femur lengths, but no other abnormalities. At birth, the child was noted to have multiple dysmorphic features, including short humeri and femurs, coarse facial features, retrognathia and yellowish hypertrophic gums in addition to hyperbilirubinaemia and thrombocytopenia. Radiological studies demonstrated bony demineralization with profound diaphyseal cloaking in the long bones. Genetic testing diagnosed I-cell disease.