RESUMEN
The Yemenite deaf-blind hypopigmentation syndrome was first observed in a Yemenite sister and brother showing cutaneous hypopigmented and hyperpigmented spots and patches, microcornea, coloboma and severe hearing loss. A second case, observed in a girl with similar skin symptoms and hearing loss but without microcornea or coloboma, was reported as a mild form of this syndrome. Here we show that a SOX10 missense mutation is responsible for the mild form, resulting in a loss of DNA binding of this transcription factor. In contrast, no SOX10 alteration could be found in the other, severe case of the Yemenite deaf-blind hypopigmentation syndrome. Based on genetic, clinical, molecular and functional data, we suggest that these two cases represent two different syndromes. Moreover, as mutations of the SOX10 transcription factor were previously described in Waardenburg-Hirschsprung disease, these results show that SOX10 mutations cause various types of neurocristopathy.
Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas del Grupo de Alta Movilidad/genética , Hipopigmentación/genética , Secuencia de Aminoácidos , Células Cultivadas , Anomalías Craneofaciales/genética , Análisis Mutacional de ADN , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/metabolismo , Proteínas del Grupo de Alta Movilidad/química , Factor C1 de la Célula Huésped , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas Nucleares/análisis , Factor 1 de Transcripción de Unión a Octámeros , Polimorfismo Conformacional Retorcido-Simple , Unión Proteica/genética , Estructura Terciaria de Proteína , Factores de Transcripción SOXE , Síndrome , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , YemenRESUMEN
BACKGROUND: We studied the effects of long-term treatment with interferon on histologic features of the liver and serum alanine aminotransferase concentrations in patients with chronic non-A, non-B hepatitis. METHODS: Consecutive patients who met the inclusion criteria were enrolled in the study. The diagnosis of chronic non-A, non-B hepatitis was established on the basis of the liver-biopsy findings and an abnormal serum alanine aminotransferase value (greater than 1.5 times the normal value) for at least one year. All patients were treated for six months with 3 million units of interferon alfa-2b given subcutaneously three times a week and were then randomly assigned to the same treatment for an additional 12 months (group 1), a regimen of 1 million units three times a week for 12 months (group 2), or no further treatment (group 3). Patients in group 3 who had elevated serum alanine aminotransferase concentrations for three consecutive months underwent the initial regimen once again. Follow-up continued for two years after the discontinuation of treatment. Histologic improvement was defined as a decrease of at least one grade in the score for necroinflammatory activity (0, no activity; 1, mild; 2, moderate; or 3, severe) between the first liver biopsy and a biopsy performed at 18 months. RESULTS: Of the 329 patients initially treated, 303 were randomized: 103 to group 1, 101 to group 2, and 99 to group 3. Of the 286 patients tested, 252 (88.1 percent) had antibodies to hepatitis C virus. In an intention-to-treat analysis, 46 of the patients in group 1 (44.7 percent) had normal serum alanine aminotransferase values at 18 months, as compared with 27 of the patients in group 2 (26.7 percent, P = 0.008) and 30 of those in group 3 (30.3 percent, P = 0.04). Between 19 and 42 months, 23 of the patients in group 1 (22.3 percent) continued to have normal serum alanine aminotransferase values (measured every six months), as compared with 10 of the patients in group 2 (9.9 percent, P = 0.02) and 8 of those in group 3 (8.1 percent, P = 0.005). Among the 176 patients with repeated liver biopsies at 18 months, more patients in group 1 had improved histologic-activity scores (69.6 percent) than in group 2 (47.6 percent, P = 0.02) or group 3 (38.6 percent, P < 0.001). CONCLUSIONS: Among patients with chronic non-A, non-B hepatitis, a regimen of 3 million units of interferon alfa-2b given three times a week for 18 months produced better histologic findings and serum alanine aminotransferase values than regimens involving a lower dose or a shorter duration of treatment.