[SNP array and cytogenetic analysis of a patient with unexplained mental retardation].
OBJECTIVE
To analyze a patient with unexplained mental retardation by using three primer PCR (TP-PCR) and single nucleotide polymorphisms array (SNP-array), and to correlate the genotype with phenotype.


METHODS
Peripheral blood sample was taken from the patient for the extraction of DNA. TP-PCR was used to determine the copy number of CGG repeats in the 5'UTR of the FMR1 gene. SNP array was used for high resolution analysis of the patient's genome.


RESULTS
TP-PCR has shown no abnormal amplification of CGG in the 5'UTR of FMR1 gene. Hence, Fragile X syndrome was excluded as the cause for mental retardation. SNP array analysis has identified a 0.93 Mb duplication at 7q36.1-q36.2 and a 2.2 Mb deletion at 12p13.1-p13.2 in the patient.


CONCLUSIONS
The microduplication and microdeletion discovered in the patient probably underlies the intelligence disability. The high-resolution SNP array can provide accurate information for the identification of pathogenesis, and is the preferred method for the diagnosis of unexplained mental retardation.
Prenatal Diagnosis Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China. kongxd@263.net.
Nan
N
Bai
Shiyue
S
Mei
Zhenhua
Z
Zhao
Xiangdong
X
Kong
D002648:Child; D020732:Cytogenetic Analysis; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D020641:Polymorphism, Single Nucleotide
D051860:Fragile X Messenger Ribonucleoprotein 1; C497683:FMR1 protein, human