Which of the following is not a feature of 21st trisomy?
Down's syndrome (21st trisomy) is the most common chromosomal disorder and a major cause of mental retardation. Children with Down's syndrome develop muscle hypotonia not hypeonia. Reference: Essential Paediatrics by O.P Ghai 6e page 592.
Mental retardation
Duodenal atresia
Hypeonicity
CHD