Ho Chi Minh City
Ms. Han was born with mental retardation, had multiple pregnancies, and now at the age of 27, genetic testing during in vitro fertilization discovered an abnormality in the structure of chromosome number 18.
Test results at the Reproductive Support Center, Tam Anh General Hospital, Ho Chi Minh City (IVF Tam Anh, Ho Chi Minh City), showed that Ms. Han carries structural abnormalities of chromosome number 18, repeats and 18q deletion - a rare condition. According to Master Ma Pham Que Mai, a genetic counselor, this abnormality is the cause of her congenital mental retardation and recently had to terminate her pregnancy due to a birth defect.
Ms. Han is the second child of Mrs. Hanh and her husband, 60 years old, in Lam Dong. The older brother, now 35 years old, was born with mental retardation of unknown cause, and barely interacted with his parents. Han's condition is better than her brother's, but she still learns slowly, has difficulty absorbing, has an erratic personality, has poor hearing, and is shorter than her peers. Han examined many places but could not find the cause.
In 2024, Ms. Han became pregnant, an ultrasound detected multiple malformations of the fetus, and an amniocentesis showed that the fetus had a complex deletion/duplication of chromosome 18. If born, the child is at risk of intellectual disability, mental and motor retardation, so the pregnancy must be terminated.
Ms. Han's family brought Ms. Han from Lam Dong to Ho Chi Minh City to seek treatment to give birth to a healthy baby. IVF doctor Tam Anh in Ho Chi Minh City appointed the couple to have a chromosomal test and a chromosomal microdeletion - microduplication analysis test to find the cause and evaluate the genetic risk for future pregnancies. The results showed that the husband was completely normal, while Ms. Han carried an abnormal 18q duplication and deletion in chromosome 18.
According to Master Que Mai, medical reports have recorded about 28 cases of 18p duplication, while 18q deletion syndrome is estimated to occur in about 1/40,000 live births. The simultaneous combination of these two abnormalities has not been recorded with an exact incidence. The medical literature is mainly recorded through case reports and small family groups.
Abnormalities on chromosome 18 can change the amount of genetic material in the cell, causing the patient to be affected to many different degrees depending on the location and size of the missing or duplicated chromosome segment and the genes located in this region. Commonly reported manifestations include delayed physical and mental development, delayed language development, short stature, decreased muscle tone, craniofacial abnormalities, hearing impairment, bone abnormalities and some neurological problems. Some people may have difficulties with learning, behavior and social interactions.
If she continues to get pregnant, Ms. Han is at risk of creating an embryo carrying chromosome 18 from abnormal egg gametes. "To disconnect the genetic chain of this pathology, PGT-SR embryo biopsy is the optimal method," Master Que Mai said, advising Ms. Han to perform in vitro fertilization combined with embryo screening to select normal embryos to transfer to the uterus.
MSc. Dr. Giang Huynh Nhu, Director of IVF Tam Anh Ho Chi Minh City, stimulated Ms. Han's eggs to obtain 8 oocytes, fertilized in vitro and raised 4 embryos on day 5. The biopsy results showed that 2 embryos were normal, the remaining embryos had chromosomal abnormalities. The doctor prepared the appropriate endometrium and transferred the embryo, and Ms. Han became pregnant the first time. NIPT test in the first 3 months of pregnancy shows that the fetus has no genetic abnormalities. Ms. Han gave birth to a healthy baby boy, weighing 2.8 kg. She still has one embryo frozen so she can have more children in the future.
According to Dr. Nhu, with modern pre-implantation genetic testing techniques, families have a good chance of having healthy children. At IVF Tam Anh, the techniques PGT-SR (screening for chromosomal structural abnormalities), PGT-A (screening for chromosomal aneuploidy in older women, recurrent miscarriages or multiple embryo transfer failures) and PGT-M (screening for the risk of inheriting single-gene diseases for children) have helped many couples carrying chromosomal abnormalities or genetic diseases have the opportunity to have healthy children, limiting the risk of repeating the disease in the next generation.
Couples who have had multiple miscarriages, birth defects, or have not conceived after a year of regular intercourse should have a comprehensive reproductive health examination, genetic testing if necessary, and embryo biopsy to find the cause, treat effectively, and have children soon.
