Clinical Picture of Homocystinuria from the Cystathionine b-synthaseDeficiency in Nineteen Czech and Slovak Patients

Overview

Background.
Homocystinuria due to cystathionine b-synthase deficiency is an autosomal recessive disorder ofmethionine metabolism. It manifests with vascular, central nervous system and connective tissue disturbances, andphenotypically resembles Marfan’s syndrome. We analysed the clinical course of homocystinuria in Czech andSlovak patients.Methods and Results. The group of homocystinuric patients consisted of 19 individuals (12 males and 7 females)aged 5-32 years (average age 18 years), who were diagnosed between 1980 and 1999. The overall incidence ofhomocystinuria in the Czech and Slovak Republics was 1:287,000. The proportion of pyridoxine-responsive patientswas 47 %. The average follow-up period was 10 years (range 1 month to 19 years). The prevalence of the individualsigns in the group was as follows: lens dislocation - 95 % of patients, progressive myopia - 79 %, marfanoid habitus- 74 %, kyfoscoliosis - 68 %, osteoporosis - 63 %, psychomotor retardation - 58 %, other neurologic symptomatology- 58 % and tromboembolism - 21 %. The average delay between the first sign of the disease and the time when thediagnosis was made was 4 years (range 1 to 14 years). At the time of diagnosis the average levels of metabolites inplasma were as follows: total homocysteine 348 mmol/l (range 211-536), free homocystine 70 mmol/l (range 0-203)and methionine 359 mmol/l (range 75-937).Conclusions. Both the clinical course of homocystinuria due to the cystathionine b-synthase deficiency and itsincidence in the Czech and Slovak Republics are similar to those in other populations. Since homocystinuria isa treatable disease, it should be included in the differential diagnosis of Marfan’s syndrome, tromboembolism andsevere psychomotor retardation.

Key words:
homocystinuria, homocysteine, cystathionine b-synthase, lens ectopia, psychomotor retardation,