Screening of subtelomeric rearrangements in autistic disorder: identification of a partial trisomy of 13q34 in a patient bearing a 13q;21p translocation.
Within the framework of a FISH screening protocol to detect cryptic subtelomeric rearrangements in autistic disorder (AD), a patient bearing three copies of the subtelomeric portion of the q arm of chromosome 13 has been identified. Beside AD, the patient also has severe mental retardation and displays several dysmorphic features. Further FISH analyses revealed that the trisomy was caused by the translocation of a 13q subtelomeric fragment to the acrocentric tip of one chromosome 21 [46,XY.ish der(21) t(13;21) (q34;p13)(D13S1825+)]. Gene dosage experiments carried out with three multiallelic polymorphisms of the subtelomeric region of chromosome 13q showed that the putative length of the triplicate region does not exceed 300 kb about, that is, the distance from telomere to the first normally inherited marker. In addition, gene dosage analysis performed on the derivative chromosome 21, did not reveal loss of the most telomeric protein-encoding genes on 21p. The potential relationship between a postulated increased expression of genes on 13q34 and the complex phenotype in this trisomic patient is discussed.
Di Bella
Maria Antonietta
MA
Dipartimento di Biopatologia e Metodologie Biomediche, Università degli Studi di Palermo, Palermo, Italy.
Calì
Francesco
F
Seidita
Gregorio
G
Mirisola
Mario
M
Ragusa
Angela
A
Ragalmuto
Alda
A
Galesi
Ornella
O
Elia
Maurizio
M
Greco
Donatella
D
Zingale
Marinella
M
Gambino
Giovanna
G
D'Anna
Rosalba P
RP
Regan
Regina
R
Carbone
Maria Carmela
MC
Gallo
Alessia
A
Romano
Valentino
V
D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000235:genetics*; D002648:Child; D002882:Chromosomes, Human, Pair 13; D005260:Female; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D016133:Polymerase Chain Reaction; D016615:Telomere; D014178:Translocation, Genetic; D014314:Trisomy