Abstract
Three cases of mucolipidosis III (ML-III) from two families are described. Case 1, a 15-year-old male, having severe kyphoscoliosis progressing since 3 months of age, showed joint rigidity, valvular heart disease, h epatomegaly, inguinal hernia, severe growth retardation and moderate mental retardation. Case 2, a 13-year-old male, had only mild joint stiffness and case 3, a 15-year-old female (a sister of case 2), was almost asymptomatic. Results of biochemical studies with plasma, lymphocytes and cultured skin fibroblasts of these 3 cases were compatible with those of ML-IL However, case 1 showed an intermediate clinical phenotype of mucolipidosis II (ML-II) and ML-Ill and cases 2 and 3 showed milder clinical picture than that of typical ML-III. As ML-II and ML-III share the same enzymic deficiency, it is reasonable that case 1 is diagnosed as a slow progressive late infantile type and cases 2, 3 as a juvenile type of I-cell disease.
