2-year-old Singapore boy is one of estimated 400 in world with disease caused by single altered gene
SINGAPORE - During Tizane Woo's 20-week prenatal scan, her doctor noticed something was not right with her child, Teyden Hamilton Ho."They told us that his head was smaller than average. The circumference of his hindbrain (cerebellum) was too small," said the 26-year-old housewife."A week after I went for amniocentesis in the 22nd week of my pregnancy, I was told that Teyden has an additional chromosome, which was inherited from me."She and her husband were asked if they wanted to abort the child because of all the issues he could face."But not once did we think of doing so because he was ours," Woo said.When Teyden was 15 months old, he was diagnosed with Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome after blood samples from all three of them were sent to the US for testing.The condition, named after the four doctors and researchers who identified it in 2016, is a rare hereditary disease caused by a single altered gene on a non-sex chromosome.Broadly speaking, it affects brain development.