Analysis of the clinical features of pericentric inversion of chromosome 9

Cytogenetics investigation in 151 Brazilian infertile male patients and genomic analysis in selected cases: experience of 14 years in a public genetic service

OBJECTIVES

Male infertility accounts for approximately 30% of cases of reproductive failure. The characterization of genetic variants using cytogenomic techniques is essential for the adequate clinical management of these patients. We aimed to conduct a cytogenetic investigation of numerical and structural rearrangements and a genomic study of Y chromosome microdeletions/microduplications in infertile men derived from a single centre with over 14 years of experience.

RESULTS

We evaluated 151 infertile men in a transversal study using peripheral blood karyotypes and 15 patients with normal karyotypes through genomic investigation by multiplex ligation-dependent probe amplification (MLPA) or polymerase chain reaction of sequence-tagged sites (PCR-STS) techniques. Out of the 151 patients evaluated by karyotype, 13 presented chromosomal abnormalities: two had numerical alterations, and 11 had structural chromosomal rearrangements. PCR-STS detected a BPY2 gene region and RBMY2DP pseudogene region microdeletion in one patient. MLPA analysis allowed the identification of one patient with CDY2B_1 and CDY2B_2 probe duplications (CDY2B and NLGN4Y genes) and one patient with BPY2_1, BPY2_2, and BPY2_4 probe duplications (PRY and RBMY1J genes).

Occurrence of mosaic trisomy 22 and pericentric inversion of chromosome 9 in a patient with a good prognosis

Complete trisomy 22 is a rare chromosomal condition that is incompatible with life. However, mosaic trisomy 22 usually has prolonged survival compatibility and may present a good prognosis depending on the tissues affected. Herein, we described a male patient with the occurrence of mosaic trisomy 22 associated with the inversion of chromosome 9, with karyotype 47, XY, inv (9) (p11q13), + 22 [5] / 46, XY, inv(9) (p11q13) [45] and arr 22q11.1 ~ q13.33(16,417008-51,219,009)x2 ~ 3. It is not possible to infer, in general, the clinical characteristics associated with mosaic trisomy 22. However, the patient presented common clinical features observed in reported cases (in parentheses the percentage observed comparing all reported cases): facial dysmorphia (100%), delay in motor development/growth (82%), cardiac abnormalities (73%), ear abnormalities (55%) and facial and/or body asymmetry (55%), in addition to hypotonia, skin spots, hypoplastic nails. Given the survival and quality of life associated with multidisciplinary treatment, it can be concluded that the patient has a good prognosis. Conclusively, we're presenting the occurrence of mosaic trisomy 22 and chromosome 9 inversion in the patient with favorable prognosis. Thus, this study proposed a guide which should be inserted in databases of rare genetic conditions to help genetic counselors define mosaic trisomy 22 diagnosis.

Risk Factors Associated with Recurrent Pregnancy Loss and Outcome of Pre-Implantation Genetic Screening of Affected Couples

Background:

Recurrent pregnancy loss (RPL) is a multifactorial disorder which affects up to 5% of couples around the world. Several factors are considered to be involved in RPL; but, the etiology remains unexplained in 35-60% of cases. The aim of this study was to assess the frequency of risk factors associated with RPL in a group of our clinic clients, and their pre-implantation genetic screening (PGS) outcome.

Materials and Methods:

We designed a retrospective descriptive study among, 602 Iranian couples referred to the Royan Reproductive Clinic (Tehran-Iran) from 2006 to 2018. Their karyotyping test and PGS outcomes were analyzed. PGS had been applied by array comparative genomic hybridization (array-CGH) on embryos from these patients. Also, karyotyping test had been performed using standard cytogenetic techniques.

Results:

G-banding analysis revealed a frequency of 15.61% chromosomal abnormalities in RPL couples. Also, the reciprocal translocations were more frequent (33/1204 cases) compared to the other structural abnormalities. Pregnancy rate per embryo transferred were 50% with array-CGH approach.

Conclusion:

Our findings could confirm a positive correlation between chromosomal abnormalities and RPL rate. Applying PGS for the RPL couples, leads to improvement of pregnancy success rate.