Classic homocystinuria: clinical, biochemical and radiological observations, and therapeutic outcome of 24 Saudi patients

We considered the clinical, biochemical and radiological findings, and response to pyridoxine [vitamin B6] of 24 classic homocystinuric patients [15 females, 9 males] diagnosed at King Faisal Specialist Hospital and Research Centre. Common clinical findings included ectopia lentis [20 patients], skeletal system involvement [18 patients], vascular system involvement [9 patients] and mental retardation [all patients to varying degrees]. A number of unusual findings were reported. The parents of 21 patients were first-degree relatives and 19 patients had at least one other family member affected by the same disease. Only 4 patients responded to pyridoxine; their methionine level decreased to almost normal range

Tyrosinaemia type II: an easily diagnosed metabolic disorder with a rewarding therapeutic response

We retrospectively reviewed clinical and biochemical data of four patients diagnosed with tyrosinaemia type II. Diagnosis was established by high plasma tyrosine and normal plasma phenylalanine levels using plasma high-pressure liquid chromatography and tandem mass spectrometry. All patients were mildly mentally retarded and had painful non-pruritic and hyperkeratotic plaques on the soles and palms. There were no ophthalmic symptoms. The patients dramatically responded clinically and biochemically to a diet restricted in tyrosine and phenylalanine

Biotinidase deficiency: a treatable genetic disorder in the Saudi population

Biotinidase deficiency is an autosomal recessive genetic disorder which is not uncommon in the Saudi population. Biotinidase is responsible for biotin recycling and biotin is an essential cofactor for activation of the carboxylase enzymes. Absence of biotinidase leads to infantile or early childhood encephalopathy, seizure disorder, dermatitis, alopecia, neural deafness and optic atrophy. The disease can be diagnosed by simple fluorometric enzyme assay. Treatment with biotin is both cheap and simple, resulting in rewarding clinical recovery and normalization of the biochemical, neuroradiological and neurophysiological parameters. If neglected, however, a patient may die of acute metabolic acidosis or may suffer from permanent neural deafness and optic atrophy, with mental and motor handicap. We describe the detection and treatment of 20 cases of biotinidase deficiency in our hospital and recommend the introduction of a neonatal screening programme for this disorder