Genetic Analysis of a Mosaic Fra(16)(q22)/Del(16)(q22) Karyotype in a Primary Infertile Woman

Abstract

Guiyuan He,1,* Xi Wang,1,* Beiqing Li,1 Lei Wang,1 Jing Zhang,2 Yang Shi,1 Wenxiu Zhu,1 Ming Shi1,3 1Centre for Reproductive and Genetic Medicine, Dalian Women and Children’s Medical Group, Dalian, People’s Republic of China; 2Department of Clinical Laboratory, Central Hospital of Dalian University of Technology, Dalian Municipal Central Hospital, Dalian, People’s Republic of China; 3Department of Clinical Laboratory, Dalian Women and Children’s Medical Group, Dalian, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ming Shi, Centre for Reproductive and Genetic Medicine & Department of Clinical Laboratory, Dalian Women and Children’s Medical Group, Dalian, 116037, People’s Republic of China, Email [email protected]: Fragile sites are specific chromosomal regions showing gaps, poor staining, contractions, or even breaks in the chromosomes. These spontaneous and heritable fragile sites are prone to structural variations which can lead to adverse reproductive outcomes. This paper aims to present a specific case study of a female patient, with a mosaic karyotype involving chromosome 16q22 fragile site which is very rare in clinic and her experience of infertility.Case Presentation: A 37-year-old woman is diagnosed with ten-year primary infertility. She worked in a factory, and she was occasionally exposed to paint. She underwent two cycles of follicular monitoring with intrauterine insemination (IUI) using her husband’s sperm six years ago but failed. Most of her prepregnancy tests were normal, except a not smooth right fallopian tube. Her G-band karyotype of peripheral blood lymphocytes was mos 46, XX, del(16)(q22)[40]/46, XX, fra(16)(q22)[29]/46, XX, fra(16)tr(16)(q22)[3]/46, XX[28] which inherited from her mother. The SCE assay detected a significantly higher frequency of SCEs in the 16q region of the patient’s chromosomes compared to her mother and a healthy control. However, the average SCEs per chromosome were quite close. Moreover, copy number variation (CNV) sequencing showed no deletion nor duplication at 16q22.Conclusion: Infertility cannot be completely attributed to the fragile site on chromosome 16q22. Assisted reproductive technology combined with preimplantation genetic testing may help in achieving a healthy live birth.Keywords: fragile sites, infertility, fra(16)(q22), del(16)(q22), SCE, CNV

Keywords

• fragile sites
• infertility
• fra(16)(q22)
• del(16)(q22)
• sce
• cnv