The Presence of Translocation [t(16;19)(q24;q12)x2] between Two Copy of Non-Homologous Chromosomes in a Case with Atypical Facial Appearance and Mental Retardation

Abstract

Purpose: Mental retardation is a common handicap (2-3% of the general population) with an unknown cause in more than 50% of mentally retarded patients. Important causes are chromosome abnormalities which are detectable in 4-28% of cases, depending on the patient selection and techniques used. Aim of the study was to determine possible association between atypic facial appearance, mental retardation and the translocation [t(16; 19)(q24;q12) x2] between two copy of non homolog chromosomes.

Materials and Methods: Chromosomal analysis of peripheral blood lymphocytes from the proband and her family were performed with standart protocols at the Cukurova University hospital in Turkey.

Results: We assessed the second and third generation of the family in which the translocation between chromosomes 16 and 19 segregates: one of the three progenies with the karyotype 46, XY, t(16;19)(q24; q12) was heterozygote for the translocation and presented normal phenotype. One of the three progenies with the karyotype 46, XY presented normal phenotype also and the third with the karyotype 46, XY [t(16;19)(q24;q12)x2] was the proband. The parents were consanguinous, heterozygote for the translocation, and presented normal phenotype.

Conclusions: Atypical facial appearance and mental retardation could be associated with the homozygote translocation. These findings can be used in clinical genetics and may be used as an effective tool for reproductive guidance and genetic counseling.