Distribution of the D15Z1 copy number polymorphism

Abstract

Using fluorescent in situ hybridization (FISH) with the probe p15 (D15Z1), we investigated the distribution of the polymorphic 15p signal which has been reported to occur on acrocentric chromosomes in addition to chromosome 15. The short arm of chromosome 15 has a characteristic signal pattern when hybridized with the FISH probe D15Z1. However, the D15Z1 signal can occasionally be seen on the short arm of other acrocentric chromosomes. We studied the distribution of the D15Z1 probe in 1657 patients consisting both of individuals with a normal karyotype and those with a variety of chromosome abnormalities involving the acrocentric chromosomes. Our results show that one in six individuals, regardless of their patient ascertainment category or karyotypic status, had one or more additional D15Z1 signals, and that there were no significant differences in the distribution of extra signals among the patient groups.

Translocaciones crípticas de cromosomas acrocéntricos en muestras de tejido de aborto aneuploide

“…Algunos de los más frecuentes se encuentran en los brazos cortos de los cromosomas acrocéntricos (13,14,15,21,22). Recientemente se ha sugerido que un tipo de rearreglos cromosómicos, considerados heteromorfismos y conocidos como translocaciones crípticas de cromosomas acrocéntricos, podrían ser un factor causal de las alteraciones cromosómicas numéricas o aneuploidías que se abortan en 90% de los casos.…”

“…Se extienden en segmentos tan largos como varias megabases de ADN, generalmente no codificante, y se localizan en las regiones heterocromáticas centroméricas y pericentroméricas. Las más comunes se encuentran en los cromosomas 1, 9, 16, la región distal del cromosoma Y 5 y los brazos cortos de los cromosomas acrocéntricos (13,14,15,21,22). Estas variantes se presentan en 2 a 3% de la población general, lo más frecuente es la ganancia de material heterocromático en estas regiones (1qh+, 9qh+, 16qh+ y s+).…”

“…Chromosomal heteromorphisms are normal variants, considered without phenotypic impact, some of the most frequent are in the short arms of the acrocentric chromosomes (13,14,15,21,22). Recently it has been suggested that a type of chromosomal rearrangements considered heteromorphisms, known as cryptic translocation of acrocentric chromosomes (TCA), may be an etiological factor of numerical chromosomal abnormalities or aneuploidies, which are aborted by 90%.…”

Interstitial 22q13 deletions: genes other than SHANK3 have major effects on cognitive and language development

“…FISH analysis using the probe D15Z1 showed hybridization signal on the MC, indicating that it originated most likely from chromosome 15, although we have found D15Z1 crosshybridizing polymorphisms on all the other acrocentric chromosomes. 22 Uniparental disomy of chromosome 15 was excluded by genotyping the family with four microsatellite loci (D15S822, D15S993, D15S1020 and D15S533). Patient A was heterozygous for all four loci and inherited both a paternal and maternal allele in each case (data not shown).…”

Preimplantation genetic haplotyping a new application for diagnosis of translocation carrier’s embryos- preliminary observations of two robertsonian translocation carrier families

“…Further FISH examination of the maternal metaphases using chromosome 15 centromeric probe (D15Z1), revealed that one of her chromosome 14 Translocation related alleles are indicated in bold and italic harbored a region homologues to centromere 15. One in six individuals in general population will show one or more additional centromeric D15Z1 signal [17]. Hence two of the three centromere 15 signals revealed in embryo 2, were located on chromosomes 15 and the additional one on chromosome 14.…”