Dup(4p)del(9p) in a familial mental retardation syndrome. Resemblance to de Lange syndrome detected by high-resolution banding.
A young woman with features resembling de Lange syndrome had a normal banded karyotype. Similar phenotypes were present in a maternal aunt and uncle. Utilizing high-resolution banding, the propositus was found to have a chromosomal abnormality characterized by dup(4p)del(9p). Using the same banding technique, her mother and two of her siblings were identified as having balanced reciprocal translocations. Chromosome studies with high-resolution banding should be performed in these instances even in the presence of a normal banded karyotype. Determining a chromosomal basis for the phenotype may lead to a significant reproductive risk in individuals with balanced chromosomal rearrangements and may afford them with the opportunity to pursue prenatal diagnosis.
D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D002869:Chromosome Aberrations / Q000235:genetics*; D002871:Chromosome Banding; D025063:Chromosome Disorders; D002906:Chromosomes, Human, 6-12 and X; D003635:De Lange Syndrome / Q000235:genetics*; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D010375:Pedigree