RESUMO
An infant with delayed development and multiple congenital anomalies was found to possess a duplication of 14q23 leads to qter. This imbalance arose through segregation of a maternal 14/X translocation, observed in only 28% of the mother's cells. Although the X-chromosome-derived portion of the translocation was late replicating in the proposita, the autosomal segment was not inactivated, leading to functional trisomy for distal 14q. Phenotypic comparison to cases with similar duplications does not allow the clinical description of a partial trisomy syndrome.
Assuntos
Anormalidades Múltiplas/genética , Cromossomos Humanos 13-15 , Cromossomos Sexuais , Translocação Genética , Trissomia , Cromossomo X , Bandeamento Cromossômico , Feminino , Humanos , Recém-Nascido , Cariotipagem , Mosaicismo , Fenótipo , SíndromeRESUMO
Two members of a large family had a similar multiple congenital anomalies mental retardation (MCA/MR) syndrome and an identical aberration of chromosome 16. Their mothers, who are first cousins, had a different abnormality of one chromosome 16, which appeared to be an acrocentric. We interpret these findings as an insertion of a segment of 16p into 16q. following a three-break rearrangement and meiotic crossing over. The two abnormal children have a duplication of 16p11 leads to p13. The clinical manifestations of these patients differ from those of previously reported cases of dup(16p).
Assuntos
Anormalidades Múltiplas/genética , Aberrações Cromossômicas , Cromossomos Humanos 16-18 , Troca Genética , Deficiência Intelectual/genética , Feminino , Humanos , Recém-Nascido , Cariotipagem , Masculino , Meiose , LinhagemRESUMO
Pretreatment of PHA-stimulated lymphocyte cultures from normal males with 100 micrograms/ml Distamycin A for the final 24 h of incubation led to a striking decondensation of the heterochromatic portion of the long arm of the Y chromosome. The despiralized region of Yq maintained its fluorescent properties in this altered morphologic state. Two cases of Y chromosome translocation (Y/22 and Y/X) were identified with this technique. A review of the literature revealed 62 similar cases in which the phenotypic-karyotypic correlations were instrumental in the prenatal counseling of the family with the Y/22 translocation.
Assuntos
Cromossomos Humanos 21-22 e Y , Distamicinas , Pirróis , Cromossomos Sexuais , Translocação Genética , Cromossomo Y , Bandeamento Cromossômico , Feminino , Humanos , Masculino , Gravidez , Diagnóstico Pré-NatalRESUMO
Cytogenetic evaluation of cultured amniotic fluid cells showed mosaicism of three karyotypes: 46,XY; 46,XY [t(13;17)(q13;q25]; and 46, XY [t(11;12)(p11;q13)]. Reanalysis of cells from the four original culture flasks harvested individually revealed that both translocations derived from the same flask. Repeat amniocentesis, as well as peripheral blood obtained postnatally from a phenotypically normal male infant, demonstrated only normal chromosomes (46,XY). This observation represents a case of pseudomosaicism containing two different reciprocal translocations.
