“Director Liu, I have a 45,X0 karyotype, the Y chromosome is missing, does this mean I can’t have children?”
Upon entering the consultation room, Mr. Li couldn’t wait to present his test report to Dr. Liu Huang, the Deputy Director of the Male Department at the Guangdong Provincial Reproductive Hospital.
Initially, 29-year-old Mr. Li, married for 5 years, has been unable to conceive. It was only during a check-up at a local hospital that it was discovered that after centrifuging the semen, no sperm was found, and the karyotype showed 45,X0 with the Y chromosome missing. Referred by local doctors, Mr. Li visited Dr. Liu Huang, Deputy Director of the Male Department at the Guangdong Provincial Reproductive Hospital’s expert clinic. It is reported that the majority of such patients are females, and 45,X0 males are extremely rare, with only about 30 cases reported worldwide.
45,X0 males are extremely rare
After a comprehensive examination, Dr. Liu Huang found that Mr. Li’s external genitalia were normal, with small testicles, approximately 6 milliliters in size, and routine semen tests repeatedly showed no sperm after centrifugation. Dr. Liu Huang stated, “This is a case of non-obstructive azoospermia, which also meets the clinical diagnosis of male Turner syndrome.”
What is 45,X0? It is known as “Turner syndrome,” clinically referred to as congenital ovarian dysgenesis or primary testicular failure. The majority of patients are females, with 45,X0 males being extremely rare, with only about 30 cases reported worldwide.
Professor Liu Huang explained that when a male’s karyotype is 45,X0, it is termed “male Turner syndrome,” primarily resulting from the absence of the Y chromosome, leading to primary gonadal insufficiency, reduced fertility, infertility, or azoospermia, with manifestations of underdeveloped external genitalia, small testicles, small penis, and some patients may also exhibit cryptorchidism, hypospadias, delayed development, among others.
Where did the Y chromosome go?
Where did the Y chromosome go in patients with “male Turner syndrome”? Dr. Liu Huang pointed out that the Y chromosome is unique to males and is a distinguishing feature between males and females. The Y chromosome contains many male-specific genes, including genes related to sperm production and sex determination.
In the common recombination patterns of reproductive cell division, Y-Y gene conversion and X-Y gene conversion are observed. Individuals formed through either the X-Y or Y-Y recombination pattern can be confirmed by testing specific genetic markers to ascertain the loss of certain genes during exchange and recombination. Following supplementary examinations, it was found that Mr. Li’s sperm production gene (AZF gene) and sex determination-related gene (SRY gene) were not missing, but his Y chromosome was completely absent.
Although Mr. Li’s Y chromosome is completely absent, the sperm production gene (AZF gene) and sex determination-related gene (SRY gene) on the Y chromosome were exchanged and retained during recombination. Due to the presence of the SRY gene, Mr. Li was able to develop as a male individual, hence showing atypical physical characteristics of Turner syndrome, known as “male Turner syndrome.”
Can male 45,X0 have children?
After detailed supplementary examinations and analysis, as Mr. Li’s sperm production gene (AZF gene) was not missing, Director Liu Huang prescribed a treatment plan involving “testicular microsurgical sperm extraction” and successfully obtained precious sperm from his underdeveloped testicle, resolving his fertility issues.
It can be said that Mr. Li is fortunate; despite losing the entire Y chromosome, he retained important genes on the short and long arms of the Y chromosome, enabling him to maintain male characteristics and fertility.
Article by Reporter Zhang Hua, Correspondents Zhang Jing and Cai Jiaqi
Image provided by the Interviewees
