P770: Genetic characterization of PYCR1-associated De Barsy syndrome in a Pakistani family through whole exome trio sequencing

No family history of recurrent abortion.O/E wife unremarkable.Husband tall others unremarkable.Diagnostic Workup: Chromosomal study from peripheral blood sample of the women (wife) showed one metaphase with three copies of chromosome 21.All other 19 metaphases were normal female karyotype.Interphase FISH (fluorescent in situ hybridization) was performed using Locus Specific Probe for 21q22.13-q22.2 to look for gain/loss of chromosome 21.Of a total of 200 interphase nuclei examined, 6.5% of the cells showed 3 signals for chromosome 21.This is a very low level of mosaic trisomy 21.Again this results have been confirmed with another fresh blood sample.Chromosomal study from peripheral blood sample of the husband showed presence of one metaphase with extra X chromosome while other 19 metaphases were normal male karyotype.FSH studies using probe for DXZ1 (X centromere) and SRY (Yp11.3)showed presence of 3 types of clones:-5.5% 2 signals for DXZ1 and 1 signal for SRY (47,XXY).-4.5% 2 signals for DXZ1 and 2 signal for SRY (48,XXYY).-90% 1 signal for DXZ1 and 1 signal for SRY (46,XY).