RESUMEN
We report here a patient with features of Down syndrome and tetralogy of Fallot who had a 21q22 duplication. The extent of the duplication was defined using fluorescent hybridization probes that map to the critical region on chromosome 21. Included within the interval was the cell adhesion molecule DSCAM but not the collagen COL6A1. The present case provides further support to the concept that there exists Down syndrome-associated congenital heart disease gene(s) on chromosome 21q22 and that over-expression of DSCAM may contribute to the cardiac defects of Down syndrome.
Asunto(s)
Cromosomas Humanos Par 21 , Síndrome de Down/genética , Duplicación de Gen , Tetralogía de Fallot/genética , Preescolar , Humanos , Hibridación Fluorescente in Situ , Lactante , Recién Nacido , Cariotipificación , MasculinoRESUMEN
Deletion of TWIST on 7p21 leads to Saethre-Chotzen syndrome, whereas deletion of the HOXA cluster on 7p15.2 leads to hand-foot-genital syndrome. We report here a patient with 46,XY,del(7)(p15.2p21) who had craniosynostosis, maxillary hypoplasia, prominent ear crus, rectoperineal fistula, and hypoplastic fifth fingers. Using fluorescence in situ hybridization, we demonstrated the deletion to encompass the TWIST locus and the HOXA cluster. We suggest that many, if not all, of the features of this patient could be accounted for by combined haploinsufficiency of the TWIST and HOXA cluster. Hence, the patient's phenotype may define a new contiguous gene syndrome on 7p.
Asunto(s)
Anomalías Múltiples/genética , Cromosomas Humanos Par 7/genética , Eliminación de Gen , Proteínas de Homeodominio/genética , Proteínas Nucleares/genética , Factores de Transcripción/genética , Acrocefalosindactilia/genética , Acrocefalosindactilia/patología , Ano Imperforado/genética , Preescolar , Oído Externo/anomalías , Femenino , Dedos/anomalías , Humanos , Hibridación Fluorescente in Situ , Masculino , Familia de Multigenes , Fenotipo , Síndrome , Proteína 1 Relacionada con TwistRESUMEN
Association of the pink-eye-dilution gene (P) with hypopigmentation is seen in patients who have oculocutaneous albinism type 2 (OCA2) and Prader-Willi syndrome (PWS) or Angelman syndrome (AS). However, it remains unknown whether duplication or amplification of the P gene causes hyperpigmentation. We previously reported a woman who had hyperpigmentation with a duplication of the proximal part of 15q, including the P gene. Here, we describe an additional patient with mosaicism of inv dup(15) and clinical manifestations of severe psychmoter retardation, epilepsy, and pigmentary dysplasia showing mottled and linear patterns of hyperpigmentation. His karyotype was 47,XY,+idic(15)(pter-->q14::q14-->pter)[38]/46,XY[12] de novo. Chromosomal fluorescence in situ hybridization (FISH) showed six copies of the P gene. Therefore, his cutaneous mosaicism might be caused by the presence of both normal and hyperpigmented skin due to multicopies of the P gene.
