|Figure 1 – This 10-month-old boy was evaluated for developmental delay, an enlarged abdomen, and splenomegaly.|
A 10-month old white child was admitted for evaluation of an enlarged abdomen, splenomegaly, and developmental delay.
The child had a normal gestation and birth weight. He had a right hydrocele at birth and rapid scrotal enlargement at age 3 months that led to repair of a right inguinal hernia.
Physical examination revealed a large, somewhat lethargic child with unusual facies (Figure 1). Height, 32 inches (greater than the 97th percentile for age, 50th percentile for 18 months); weight, 24.5 lb (greater than the 97th percentile for age; 50th percentile for 16 months); and head circumference, 18.5 inches (50th percentile for 12 months). He had a small anterior fontanelle with prominent forehead, mild hypertelorism, a shallow nasal bridge with clear nasal mucus discharge, and a short neck.
The child’s hands had a spadelike configuration, with ulnar deviation of the wrists.
Neuromuscular examination revealed normal muscle strength, tone, and deep tendon reflexes. Cranial nerve function was intact.
The liver edge was palpable 3 to 4 cm below the right costal margin.
Genital examination revealed a left scrotal mass with bilaterally descended testes and a small external urethral meatus.
|Figure 2 – The pedigree shows the affected boy (arrow) and several affected maternal uncles (filled squares).|
Scattered maculopapular lesions were present over the patient’s scalp, face, and neck. There was no lymphadenopathy.
The hematocrit was 38%; hemoglobin, 12.6 g/dL. The white blood cell count was normal, with granulation of the leukocytes on peripheral smear. Bone marrow analysis showed metachromatic granulation of histiocytes and leukocyte precursors. Levels of cholesterol, calcium, phosphorus, and total bilirubin were normal, as were results of tests of liver functions, routine karyotyping, electrocardiography, and skeletal survey radiography.
A family history revealed several maternal uncles with short stature; they had large heads, protruding abdomens, limited joint extension, hearing loss, poor vision, hernias, and cardiac abnormalities (Figure 2). A maternal great-uncle also had similar symptoms.
To what genetic disorder does this profile point?
1. Lonergan CL, Payne AR, Wilson WG, et al. What syndrome is this? Hunter syndrome. Pediatr Dermatol. 2004;21:679-681.
2. Froissart R, Maire I, Millat G, et al. Identification of iduronate sulfatase gene alterations in 70 unrelated Hunter patients. Clin Genet. 1998;53:362-368.
3. Wilson GN, Cooley WC. Preventive Health Care for Children with Genetic Conditions: Providing a Medical Home. Cambridge University Press: Cambridge, UK. 2006.
4. Vellodi A, Young E, Cooper A, et al. Long-term follow-up following bone marrow transplantation for Hunter disease. J Inherit Metab Dis. 1999;22:638-648.
5. Braun SE, Aronovich EL, Anderson RA, et al. Metabolic correction and cross-correction of mucopolysaccharidosis type II (Hunter syndrome) by retroviral-mediated gene transfer and expression of human iduronate-2-sulfatase. Proc Natl Acad Sci U S A. 1993;90:11830-11834.
6. Muenzer J, Wraith JE, Beck M, et al. A phase II/III clinical study of enzyme replacement therapy with idursulfase in mucopolysaccharidosis II (Hunter syndrome) [published correction appears in Genet Med. 2006;8:599]. Genet Med. 2006;8:465-473.
For more Information:
Wraith JE, Beck M, Giugliani R et al. Initial report from the Hunter Outcome Survey. Genet Med. 2008;10:508-516
Wraith JE, Scarpa M, Beck M et al. Mucopolysaccharidosis type II (Hunter syndrome): a clinical review and recommendations for treatment in the era of enzyme replacement therapy. Eur J Pediatr. 2008;167:267-277.