RESUMEN
Phosducin was evaluated as a candidate gene for the recessive retinal degeneration in the Abyssinan cat, rdAc, using reverse transcription and polymerase chain amplification. The nucleotide sequence of the cat phosducin coding region was determined except for 23 bp at the 5' end. Single-strand conformation analysis of a silent polymorphism within the coding region established the nonlinkage of the phosducin gene with the rdAc locus.
Asunto(s)
Proteínas del Ojo/genética , Genes Recesivos , Fosfoproteínas/genética , Proteínas Quinasas/genética , Degeneración Retiniana/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Gatos , ADN , Reguladores de Proteínas de Unión al GTP , Datos de Secuencia Molecular , Reacción en Cadena de la PolimerasaRESUMEN
X-linked progressive cone dystrophy (COD1) causes progressive deterioration of visual acuity, deepening of central scotomas, macular changes, and bull's-eye lesions. The cone electroretinography (ERG) is variably abnormal in affected males, and the rod ERG may also be abnormal. The clinical picture of heterozygous females ranges from asymptomatic to a widespread spectrum of cone-mediated dysfunction. A prior linkage study demonstrated linkage between the COD1 locus and the marker locus DXS84, assigned to Xp21.1, with no recombination. In the present study, we have clinically characterized a large four-generation family with COD1 and have performed a linkage analysis using seven polymorphic markers on the short arm of the X chromosome. No recombination was observed between the disease and the marker loci DXS7 and MAOA, suggesting that the location of COD1 is in the region Xp11.3, distal to DXS84 and proximal to ARAF1.
Asunto(s)
Ligamiento Genético , Células Fotorreceptoras Retinianas Conos/patología , Retinitis Pigmentosa/genética , Cromosoma X/genética , Niño , Mapeo Cromosómico , Femenino , Fondo de Ojo , Marcadores Genéticos , Humanos , Masculino , Linaje , Reacción en Cadena de la Polimerasa , Polimorfismo Genético/genética , Polimorfismo de Longitud del Fragmento de Restricción , Recombinación Genética , Retinitis Pigmentosa/patología , Caracteres SexualesRESUMEN
The authors report a case of Möbius syndrome with Poland syndrome, cleft palate, dextrocardia, mandibular hypoplasia, and multiple areas of diffuse brain volume loss. Karyotype demonstrated a t(1;11)(p22;p13) translocation in the patient and his phenotypically normal father and brother. This case extends the spectrum of congenital disorders that are associated with Möbius syndrome and raises the possibility of genetic heterogeneity for the Möbius disorder.