A de novo marker chromosome derived from 9p in a patient with 9p partial duplication syndrome and autism features: genotype-phenotype correlation.
BACKGROUND
Previous studies focusing on candidate genes and chromosomal regions identified several copy number variations (CNVs) associated with increased risk of autism or autism spectrum disorders (ASD).


METHODS
We describe a 17-year-old girl with autism, severe mental retardation, epilepsy, and partial 9p duplication syndrome features in whom GTG-banded chromosome analysis revealed a female karyotype with a marker chromosome in 69% of analyzed metaphases. Array CGH analysis showed that the marker chromosome originated from 9p24.3 to 9p13.1 with a gain of 38.9 Mb. This mosaic 9p duplication was detected only in the proband and not in the parents, her four unaffected siblings, or 258 ethnic controls. Apart from the marker chromosome, no other copy number variations (CNVs) were detected in the patient or her family. Detailed analysis of the duplicated region revealed: i) an area extending from 9p22.3 to 9p22.2 that was previously identified as a critical region for the 9p duplication syndrome; ii) a region extending from 9p22.1 to 9p13.1 that was previously reported to be duplicated in a normal individual; and iii) a potential ASD locus extending from 9p24.3 to 9p23. The ASD candidate locus contained 34 genes that may contribute to the autistic features in this patient.


CONCLUSIONS
We identified a potential ASD locus (9p24.3 to 9p23) that may encompass gene(s) contributing to autism or ASD.
Abu-Amero
Khaled K
KK
Ophthalmic Genetics Laboratory, Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia. abuamero@gmail.com
Hellani
Ali M
AM
Salih
Mustafa A
MA
Seidahmed
Mohammad Z
MZ
Elmalik
Tageldin S
TS
Zidan
Ghassan
G
Bosley
Thomas M
TM
D000293:Adolescent; D001321:Autistic Disorder / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D005260:Female; D056726:Genetic Association Studies; D005819:Genetic Markers; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D011247:Pregnancy; D013577:Syndrome
D005819:Genetic Markers