Toward quality assurance for metaphase FISH: a multicenter experience.

Although fluorescent in situ hybridization (FISH) is rapidly becoming a part of clinical cytogenetics, no organization sponsors multicenter determinations of the efficacy of probes. We report on 23 laboratories that volunteered to provide slides and to use a probe for small nuclear ribonucleoprotein polypeptide N (SNRPN) and a control locus. Experiences with FISH for these laboratories during 1994 ranged from 0 to 645 utilizations (median = 84) involving blood, amniotic fluid, and bone marrow.

Toward quality assurance for metaphase FISH: a multi-center experience.

Although fluorescent in situ hybridization (FISH) is rapidly becoming a part of clinical cytogenetics, no organization sponsors multi-center determinations of the efficacy of probes. We report on 23 laboratories that volunteered to provide slides and to use a probe for SNRPN and a control locus. Experiences with FISH for these laboratories during 1994 ranged from 0 to 645 utilizations (median = 84) involving blood, amniotic fluid and bone marrow.

Duplication 8p syndrome: studies in a family with a reciprocal translocation between chromosomes 8 and 12.

We report a family in which six individuals were carriers of a translocation between chromosomes 8 and 12. The balanced carriers had a chromosomes constitution: 46,XX or 46,XY,t(8;12)(021;p13). Six individuals in five generations were mentally retarded.

Familial Turner syndrome.

Seven women in three generations of a family have been affected by Turner syndrome. Turner phenotype in this family is the result of deletion of the entire short arm of one X chromosome. The short arm deletion is transmitted by carriers of a balanced X-1 translocation.

Partial trisomy of the long arm of human chromosome 1 as demostrated by in situ hybridization with 5S ribosomal RNA.

In a newborn boy with multiple malformations, a tandem duplication was detected at the distal end of the long arm of one human chromosome 1. The Giemsa bands, 1q31 to 1q43--44, were repeated serially. Since 5S rRNA genes are located at 1q42--43, in situ hybridization of 125I 5S rRNA with fixed chromosome preparations was used to confirm the chromosomal duplication.