Maternal uniparental disomy of chromosome 14 in a boy with t(14q14q) associated with a paternal t(13q14q)
- McMaster Univ., Ontario (Canada); and others
An 11-year-old boy was referred for chromosomal analysis because of precocious development and behavioral problems suggestive of the fragile X syndrome. The cytogenetic fragile X studies were normal, but a routine GTG-banded karyotype revealed an abnormal male karyotype with a Robertsonian translocation between the two chromosome 14`s: 46,XY,t(14q14q). Paternal karyotyping revealed another abnormal karyotype: 46,XY,t(13q14q). A brother had the same karyotype as the father; the mother was deceased. In order to determine if the apparently balanced t(14q14q) in the proband might be the cause of the clinical findings, molecular analysis of the origin of the chromosome 14`s was initiated. Southern blotting and hybridization with D4S13 showed that the proband had two copies of one maternal allele which was shared by his brother. The brother`s second allele corresponded to one of the paternal alleles; the proband had no alleles from the father. Analysis of four other VNTRs demonstrated the probability of paternity to be greater than 99%. Thus, the t(14q14q) was most likely composed of two maternal chromosome 14`s. Further characterization of the t(14q14q) by dinucleotide repeat polymorphic markers is in progress to determine whether it has arisen from maternal isodisomy or heterodisomy. Several cases of uniparental disomy for chromosome 14 have been reported recently. Paternal disomy appears to be associated with more severe congenital anomalies and mental retardation, whereas maternal disomy may be associated with premature puberty and minimal intellectual impairment. The origin of the t(14q14q) in the present case may be related to the paternal translocation, as the segregation of the t(13q14q) in meiosis could lead to sperm that are nullisomic for chromosome 14.
- OSTI ID:
- 133771
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0503
- 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
Similar Records
Structural rearrangements of chromosome 15 satellites resulting in Prader-Willi syndrome suggest a complex mechanism for uniparental disomy
Segregation of a paternal insertional translocation results in partial 4q monosomy or 4q trisomy in two siblings