Molecular characterization of small supernumerary marker chromosomes derived from chromosome 14/22 detected in adult women with fertility problems

Abstract

Rationale: Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes, which can be detected in patients with developmental retardation, infertile problems, and prenatal fetus. We report 3 adult female with fertility problems carrying sSMC(14/22) and aim to explore the correlation between sSMC(14/22) and fertility problems in women. Patient concerns: Three Chinese female patients were referred for infertility consultation in our hospital. Diagnoses: The karyotype of these 3 patients were 47, XX, +mar. The chromosome microarray analysis (CMA) detected various chromosomal duplications and deletions in the 3 cases: a 0.49Mb gain of 5q32 for case 1; a 0.54Mb gain of 14q32.33 and a 1.83Mb gain of 16p11.2 for case 2; a 0.37Mb loss of 13q21.2q21.31 and a 0.12Mb gain of Xp11.2 for case 3. Fluorescence in situ hybridization (FISH) using the specific probes for chromosomes 13/21, 14/22, and 15 was applied to identify the origination of these sSMC, which were all finally identified as sSMC(14/22). Interventions: Case 1 underwent the artificial reproductive technology to get her offspring and finally delivered a healthy male infant at 39 weeks. Case 2 did not plan to choose in vitro fertilization (IVF) to get offspring. Case 3 refused to do assisted reproductive technology. Outcomes: The genotype–phenotype correlation of sSMC(14/22) remain unclear. However, the existence of sSMC(14/22) might negatively affect the fertility ability in sSMC female carriers. Lessons: The combined application of traditional banding technique and molecular cytogenetic techniques can better identify more details of sSMC. For sSMC carriers with fertility problems, they could get their offsprings through assisted reproductive technologies after comprehensive fertility assessment.