Mosaic isochromosome 20q detected at amniocentesis: A likely cell culture artifact

Isochromosome Xq in Mosaic Turner syndrome

A 17-year old female has been referred for karyotyping and genetic counseling. Proband had primary amenorrhea, short stature and poorly developed secondary sexual characteristics. Ultrasound scanning showed hypoplastic uterus and gonadal dysgensis. Chromosomal analysis revealed the mosaic status for the isochromosome formation in the long arm of X, i(Xq). Proband had 3 cell lines. Her karyotype...

A 20q deletion originating in a pluripotent stem cell.

Isochromosome 12p-positive pineal germ cell tumor.

We report the chromosomal characteristics of a recurrent pineal non-seminomatous germ cell tumor in a 16-year-old male patient. This non-seminomatous tumor had the following components: embryonal carcinoma, teratoma, yolk sac tumor, and trophoblastic giant cells. Chromosome analysis showed a near-triploid karyotype (64 chromosomes), including two copies of an isochromosome 12p. This latter find...

Prenatal detection of short arm deletion and isochromosome 18 formation investigated by molecular techniques.

A patient was referred for amniocentesis because of advanced maternal age and polyhydramnios. The fetal karyotype was a mosaic 46,XX,del(18)(p11.1)/46,XX,-18,+i(18q)de novo. The deletion appeared to encompass the whole short arm as evidenced by G banding and in situ hybridisation. However, telomere sequences were found on both ends of the deleted chromosome as well as the isochromosome. The nor...

Mosaic ratio quantification of isochromosome 12p in Pallister–Killian syndrome using droplet digital PCR

BACKGROUND Pallister-Killian syndrome (PKS) is a prototypic mosaic aneuploidy syndrome caused by mosaic supernumerary marker isochromosome 12p. Cells possessing the isochromosome 12p rapidly diminish after birth in the peripheral blood, often necessitating a skin biopsy for diagnosis. Therefore, a genomic testing that is capable of detecting low percent mosaic isochromosome 12p is preferred for...