Mosaic variegated aneuploidy with microcephaly: A rare cytogenetic syndrome
- Georgetown Univ. Medical Center, Washington, DC (United States); and others
The term {open_quotes}mosaic variegated aneuploidy with microcephaly{close_quotes} describes the finding of a variety of chromosomal aneuploidies within the same individual. This mutation affecting mitotic segregation has been reported previously in only 7 persons. We report here on male and female siblings with this condition. Proband 1 died at 57 days of age; proband 2 is 7 months old. Amniocentesis performed on the first sibling only revealed multiple aneuploidies (+2, +6, +X, tetrasomy 2, double trisomy X and 11, and deletion Xq); the majority of cells were normal and the abnormal cells did not constitute true mosaicism. Postnatally, blood on proband 1 had 20/50 cells (40%) with +18, single cells with +10 and +20, and 28/50 normal cells (56%). This was initially interpreted as trisomy 18 mosaicism not detected in amniocytes. Blood from proband 2 showed the following; after 48 hrs in culture, 4/50 trisomic cells (+3, +6, +18, XXY); after 72 hrs 3/50 trisomic cells (+5, +6, +18); after 96 hrs, 7/50 aneuploid cells (+2, +8, +9, +10, +18, double trisomy 11 and 18, tetrasomy 2 with +18). Skin biopsy on proband 2 revealed trisomy 2 in 5/140 cells (4%), one cell each +18 and +19, on cell tetrasomy 2, one cell XXY and +5; 131 cells (94%) were normal. Paternal skin fibroblasts had trisomy 6 in 2/100 cells and 1 cell trisomy 5; the remainder were normal. One trisomic cell (+18) in 100 was found in maternal skin fibroblasts. Trisomy 18 was the most common aneuploidy in the probands` blood. Aneuploidy for chromosomes 2 and X were more common in amniocytes and skin. No trisomies of chromosomes 1, 4, 12-17, 22 or Y were observed; acrocentrics rarely malsegregated. These findings are consistent with those of the other 7 reported patients, and constitute a distinct syndrome of multiple chromosomal aneuploidies associated with microcephaly. Although rare, cytogeneticists and clinical geneticists should be aware of this mitotic mutant.
- OSTI ID:
- 133720
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0451
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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