RESUMEN
Hereditary predisposition to lipomas is observed in familial multiple lipomatosis (OMIM 151900) and benign cervical lipomatosis (OMIM 151800) and can also be associated with mutations in the MEN1 and PTEN genes (OMIM 131100 and 153480, respectively). In addition, a recent report indicates that a few patients with hereditary retinoblastoma also have lipomas. Here we report on an extended family segregating a splice site mutation in the RB1 gene. Almost all adult carriers of this mutation had multiple lipomas while penetrance for retinoblastoma was incomplete. In an unrelated pedigree, which was reported previously, the identical mutation was only associated with low-penetrance retinoblastoma but not lipomas. Our data indicate that lipoma predisposition in hereditary retinoblastoma is not associated with specific RB1 gene mutations but is influenced by modifying factors linked to this gene.
Asunto(s)
Lipomatosis Simétrica Múltiple/genética , Proteína de Retinoblastoma/genética , Retinoblastoma/genética , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Humanos Par 13/genética , ADN/química , ADN/genética , Análisis Mutacional de ADN , Salud de la Familia , Femenino , Predisposición Genética a la Enfermedad , Humanos , Lipomatosis Simétrica Múltiple/complicaciones , Escala de Lod , Masculino , Mutación , Linaje , Penetrancia , Retinoblastoma/complicacionesRESUMEN
Breath hydrogen (H2) analysis, as used in gastroenterologic function tests, requires a stationary analysis system equipped with a gaschromatograph or an electrochemical sensor cell. Now a portable breath H2-analyzer has been miniaturized to pocket size (104 mm x 62 mm x 29 mm). The application of this device in clinical practice has been assessed in comparison to the standard GMI-exhaled monitor. The pocket analyzer showed a linear response to standards with H2-concentrations ranging from 0-100 ppm (n = 7), which was not different from the GMI-apparatus. The correlation of both methods during clinical application (lactose tolerance tests, mouth-to-coecum transit time determined with lactulose) was excellent (Y = 1.08 X + 0.96; r = 0.959). Using the new device, both, analysis (3 s vs. 90 s) and the reset-time (43 s vs. 140 s) were shorter whereas calibration was more feasible with the GMI-apparatus. It is concluded, that the considerably cheaper pocket-sized breath H2-analyzer is as precise and sensitive as the GMI-exhaled monitor, and thus presents a valid alternative for H2-breath tests.
