Background: Mucolipidoses II/III (ML) are rare autosomal recessive lysosomal storage disorders (incidence: 1/325 000 live births). They have overlapping clinical phenotypes with mucopolysaccharidosis disorders and include growth retardation, facial dysmorphism, skeletal abnormalities, respiratory and heart diseases, hepatosplenomegaly and abdominal hernias. There is no specific treatment and the management has been limited to supportive care.
Case presentation: A.M., aged 18, boy of an young non-consanguineous apparently healthy couple, suspected by the Genetics Department for mucopolysaccharidosis, was first addressed to the Endocrinology Department at the age of 14 years 4 months for investigations of growth retardation. The clinical examination revealed short stature (−4 S.D.), elf facies, limited extension and abduction of the upper limbs with bilateral tendon retraction of the fingers and also in the radiocarpal and elbow joints, decreased mobility of the spine and waddling walk with wide support base; no signs of pubertal onset. Wrist radiography revealed delayed bone age of ~6 years. Somatotropic axis investigations revealed low IGF1 (62.4 ng/ml, N=220972, GH=0.42 ng/ml, without stimulation at the arginine test: GH=2.75 ng/ml) pleading for GH deficiency. Since there were not known contraindications, GH replacement therapy was started with an initial dose of 0.035 mg/kg per day followed by biannual reassessments. After 4 years of treatment the medium growth rate was 0.42 cm/month and no side effects were reported. The last wrist radiography revealed delayed bone age (11 years 6 months) permitting treatment continuation. Further investigations (the enzymes α-iduronidase, iduronate-2-sulfatase, arylsulfatase B, β-galactosidase) confirmed MLII/III.
Conclusions: Corroborating the clinical phenotype, biological data and evolution, this case can be included in MLIII. We havent found in the literature any case of MLIII treated with GH replacement therapy. In our case the treatment was effective and improved the patients quality of life.
01 Oct 2015 - 03 Oct 2015