Fraccaro Syndrome (49,XXXXY): Case study in antenatal and postnatal from South Indian patients, an awareness to the human society

Abstract

Aim: 49, XXXXY syndrome is a rare chromosomal abnormality with an approximate incidence of 1:85000 – 1:100000. Early diagnosis is important to improve the quality of life of patient. This study was carried out to assess the chromosomal abberations in prenatal and postnatal sample of patients through cytogenetics study. Methodology: Sex chromosomal aneuplodies were performed in both amniotic fluid and peripheral venous blood samples. Cytogenetic studies such as Karyotyping was done in in-vitro culture cells by GTG banded metaphase slides. FISH test was conducted in raw sample to rule out low grade mosaicism and DNA isolated from both the samples to rule out the gain and loss of genes by Chromosomal microarray technique. Results: The two cases performed showed aneuploidy with pentasomy sex chromosomes in Karyotyping in all the metaphase analysed and FISH test resulted with five signals in sex chromosome with four copies of X chromosomes and one copy of Y chromosome in all the cells. There was no loss of genes and only gain of genes in X chromosomes as identified in Chromosomal microarray. Interpretation: Based on the findings, antenatal screening is essential and should not be avoided for any USG findings and biochemical screening. The test should not be limited only to trisomy studies. Extensive studies should be performed to rule out the genetic disorders. Chromosomal aneuploidies can be identified by cytogenetic studies like Karyotyping, FISH and Chromosomal microarray technique. Key words: Aneuploidy, Chromosomal microarray analysis, Cytogenetics, Fraccaro syndrome, Karyotyping, Pentasomy sex chromosome