Prenatal studies of a family with 4p- mosaicism
- Albert Einstein College of Medicine, Bronx, NY (United States)
Mosaicism for an autosomal structural abnormality is rare. Only two cases have been reported for mosaicism involving a deletion of the short arm of number 4 chromosome (one prenatal and one postnatal). We report mosaicism for 4p- in the amniocyte cultures from a G3P2 41-year-old patient who had amniocentesis for advanced maternal age. Chromosome analysis of amniotic cultures by in situ and flask methods in Chang-supplemented McCoy`s medium revealed a mosaic karyotype, 46,XX/46,XX,del(4)(p13) with 15 (62.5%) and 9 (37.5%) metaphases, respectively. Parental blood chromosome studies yielded a paternal mosaic karyotype with 2 out of 98 cells (2%) exhibiting a deletion in the short arm of number 4 chromosome (46,XX,del(4)(p13)) as seen in the fetus. After genetic counseling, the family decided to terminate the pregnancy. Studies of fetal tissue confirmed the amniocentesis results for 4p- mosaicism (18.3%). Cytogenetic studies in father confirmed mosaicism for 4p- in fibroblast cultures from skin (2%). In none of the blood or skin fibroblast cultures was there evidence of a spontaneous fragile site at 4p13. However, cytogenetic studies of peripheral blood under conditions of folate deprivation (medium 199) showed a fragile site at 4q13 in 30% of the metaphases and 4p- cells are absent. The coincidence of the breakpoints and folate-induced fragile site in 4p- may be related phenomena in this family.
- OSTI ID:
- 134830
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-1569
- 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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