Trisomía parcial 9p derivada de una translocación recíproca 9;15, materna. Reporte de casos

Abstract

Objectives: to highlight the importance of performing karyotype in children with congenital malformations in order to have a confirmatory diagnosis, in parents to exclude the possibility of being carriers of chromosomal abnormalities and perform the genetic counseling. Clinical cases description: Female patient with 3 years and 2 months old to whom karyotype was performed by global neurodevelopmental delay and microcephaly, and her mother with 34 years old without any clinical manifestations, to both patients, lymphocyte culture and chromosomal analysis with a High Resolution Banding techniques GTG and C were performed. The mother’s karyotype was 46,XX,t(9;15)(q10;q10)(p10;p10),add14p. The father’s karyotype was normal, 46,XY, and the girl’s karyotype resulted in a pure Trisomy 9p: 47,XX,+del(9)(q11). Discussion: This chromosomal rearrangement in mother included a nonhomologous reciprocal translocation between the long arms of pair chromosomes 9 and 15 and between the short arms of the same chromosomes, additional to it, an unknown origin material was also observed in short arm from one chromosome of the 14 pair. In meiosis of this type of rearrangement, the father’s normal homologous chromosomes are paired with the mother’s translocated chromosomes and as a result of 3:1 segregation a gamete with one chromosome else was originated that after fertilization resulted in an unbalanced translocation confirming the pure trisomy in the patient.