RESUMEN
Williams-Beuren syndrome (WBS) is a contiguous gene syndrome that occurs mainly sporadically, with an estimated frequency of 1:13,700 to 1:25,000 [Grimm and Wesselhoeft, 1980; Martin et al., 1984; Udwin, 1990]. The cases of monozygotic twins concordant for WBS and dizygotic twins discordant for the syndrome have been reported. In addition, a few familial cases have been described since 1993. The clinical diagnosis has been supported by molecular genetic findings in only two patients, however. We herein report on two families in which the WBS was inherited in girls from their mothers. All four patients showed the typical hemizygous deletion at 7q11.23 [46,XX, ish,del(7)(q11.23q11.23) (ELN/LIMK1/D7S-613x1, D7S486/D7S522x2)], but the clinical picture was strikingly variable within and between families.
Asunto(s)
Síndrome de Williams/patología , Adolescente , Adulto , Niño , Preescolar , Deleción Cromosómica , Cromosomas Humanos Par 7/genética , Salud de la Familia , Femenino , Humanos , Lactante , Masculino , Síndrome de Williams/genéticaRESUMEN
Microdissection in combination with reverse painting fluorescence in-situ hybridization (FISH) is a very effective method to identify breakpoints and rearrangements of derived chromosomes and reveal the chromosomal origin of marker chromosomes. We describe an innovation that allows a convenient, fast and safe isolation of microdissected fragments as currently available protocols. The microdissected chromosomes are harvested in a collection drop located in a movable micropipette adjusted to a second micromanipulator under microscopic observation. We used this technique to analyze several cytogenetic aberrations. In order to evaluate the efficiency of our microdissection procedure, we compared the results obtained with microdissection probes made from only one fragment with those obtained with more than six microdissected fragments. In all cases, the single-fragment microdissections were sufficient to provide probes.
Asunto(s)
Pintura Cromosómica/métodos , Cromosomas Humanos , Translocación Genética , Sondas de ADN , Femenino , Humanos , Cariotipificación , Linfocitos/ultraestructura , Masculino , Reacción en Cadena de la PolimerasaRESUMEN
Two children are described with the combination of aplasia cutis congenita (ACC) and transverse limb defects known as Adams-Oliver syndrome. Whereas in the first child the typical features of ACC, syndactyly and transverse nail dystrophy were only mildly expressed and associated defects of the central nervous system and cardiac malformations were absent, the second child suffered from a very severe expression of the syndrome, with a combination of ACC, syndactyly, cutis marmorata telangiectatica congenita and multiple cardiac and central nervous system malformations which resulted in fatal central respiratory insufficiency.