RESUMO
Refsum disease is a genetic progressive neurological disorder caused by neurotoxic phytanic acid, a nutritional component patients are unable to metabolize. Symptoms include retinopathy, polyneuropathy, ataxia, and deafness. They are variable and rarely recognized before adulthood. The authors report the case of a 14-year-old girl diagnosed because of night blindness. They treated her with a phytanic acid-poor diet and extracorporeal lipid apheresis. They used different methods over a 30-month period. Thereafter, the patient was treated with diet only. Membrane filtration and heparin-induced extracorporeal low-density lipoprotein precipitation apheresis were well tolerated. Withdrawal of phytanic acid was studied quantitatively. During a 5-year period, blood phytanic acid levels decreased to a noncritical range. The patient remained free of ophthalmological and neurological progression for a total observation of 12 years. Early diagnosis and effective measures to keep the phytanic acid load low can probably prevent the serious sequelae of Refsum disease. Developing a method for newborn screening is desirable.
Assuntos
Lipoproteínas LDL/administração & dosagem , Cegueira Noturna/dietoterapia , Cegueira Noturna/etiologia , Doença de Refsum/complicações , Doença de Refsum/prevenção & controle , Adolescente , Feminino , Humanos , Estudos Longitudinais , Oxigenases de Função Mista/genética , Mutação/genética , Ácido Fitânico/sangueRESUMO
A 24-year-old male, who suffered since childhood from a progressive form of ataxia associated with peripheral neuropathy, was found severely deficient in serum vitamin E. He walked with bilateral aid and presented severe dysmetria of the limbs and dysarthric speech; muscular strength and trophism were slightly diminished in the distal muscles of four limbs and there was hypotonia of the arms; he presented absent deep tendon reflexes, bilateral Babinski's sign, reduced proprioception at four limbs, pes cavus and fasciculations of the tongue. Intestinal fat malabsorption and other gastrointestinal or haematological conditions associated with deficiency of this vitamin were ruled out. In this patient, after 2 years of a daily supplement of high doses of vitamin E, a further progression of the disease was not observed and, moreover, the neurophysiological characteristics of his neuropathy appeared clearly improved. A longitudinal evaluation of serum vitamin E levels showed values in the normal range after 13 months of therapy. The patient had molecular genetic analysis of chromosome 8 and was found homozygous for the unusual mutation 513insTT in the alpha-tocopherol transfer protein gene.