[Genetic analysis of a mental retardation patient with a rare karyotype involving complex rearrangements of five chromosomes].

OBJECTIVE: To explore the genetic cause of a female patient with severe mental retardation and a history of adverse pregnancy.

METHODS: The patient was subjected to G-banded chromosome analysis and single nucleotide polymorphism array (SNP-array) assaying. The correlation between genomic variations and the phenotype was explored.

RESULTS: The patient was found to have a complex chromosome rearrangement involving 5 chromosomes. The karyotypes of her parents were both normal. SNP-array assay has identified a 1.6 Mb microdeletion at chromosome 15q21.3 which involved 15 RefSeq genes and a 0.5 Mb microdeletion at 5q21.1 which involved one RefSeq gene.

CONCLUSION: The microdeletions, which involved TCF12, ADMA10 and AQP9 genes, probably underlie the mental retardation shown by the patient.