Translocations involving 4p16.3 in three families: deletion causing the Pitt-Rogers-Danks syndrome and duplication resulting in a new overgrowth syndrome.
Three families are reported who have a translocation involving 4p16.3. Nine subjects are described with the clinical features of the Pitt-Rogers-Danks (PRD) syndrome confirming pre- and postnatal growth failure, microcephaly, severe mental retardation, seizures, and a distinctive facial appearance; a deletion of 4p16.3 was seen in all eight patients studied with fluorescence in situ hybridisation (FISH). Eleven subjects had a new syndrome with physical overgrowth, heavy facial features, and mild to moderate mental handicap; a duplication of the chromosome region 4p16.3 was found in the four subjects studied. It is suggested that the growth abnormalities in these two families may be explained by a dosage effect of the fibroblast growth factor receptor gene 3 (FGFR3), which is located at 4p16.3, that is, a single dose leads to growth failure and a triple dose to physical overgrowth. We describe the molecular mapping of the translocation breakpoint and define it to within locus D4S43.
Partington
M W
MW
Hunter Genetics, New South Wales, Australia.
Fagan
K
K
Soubjaki
V
V
Turner
G
G
D000015:Abnormalities, Multiple / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002894:Chromosomes, Human, Pair 4; D004200:Diseases in Twins; D005260:Female; D017353:Gene Deletion; D005819:Genetic Markers; D006130:Growth Disorders / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011247:Pregnancy; D011505:Protein-Tyrosine Kinases; D051498:Receptor, Fibroblast Growth Factor, Type 3; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics; D014178:Translocation, Genetic
D005819:Genetic Markers; D017468:Receptors, Fibroblast Growth Factor; C496365:FGFR3 protein, human; D011505:Protein-Tyrosine Kinases; D051498:Receptor, Fibroblast Growth Factor, Type 3