Is Down syndrome incomplete or codominant?

Is Down syndrome incomplete penetrance?

Thus attempts have been made to define a ‘Down syndrome chromosome region’ or ‘Down syndrome critical region’ for certain traits (for example, see 11–13, 36–38). These associations are extremely difficult to find owing to the incomplete penetrance of most DS traits and the small sample size.

What are the phenotypes of Down syndrome?

This region was associated with several of the major DS phenotypes, including protruding tongue and flat facies (largely a function of hypoplastic mandible and craniofacial skeleton, respectively), short stature, mental retardation, joint hyperlaxity, muscle hypotonia, and a variety of dermatoglyphic abnormalities.

Is Down syndrome single gene or multifactorial?

While consensus among scientists is that Down syndrome is a “polygenic condition,” a condition caused by increased activity of more than one gene, it is also agreed that not all genes on chromosome 21 would contribute equally to the condition.

Can two parents with Down syndrome have a normal baby?

Parents with one baby with regular trisomy 21 are usually told that the chance of having another baby with Down’s syndrome is 1 in 100. Very few families are known who have more than one child with Down’s syndrome, so the real chance is probably less than this.

What are autosomal genetic disorders?

To have an autosomal recessive disorder, you inherit two mutated genes, one from each parent. These disorders are usually passed on by two carriers. Their health is rarely affected, but they have one mutated gene (recessive gene) and one normal gene (dominant gene) for the condition.

IT IS INTERESTING:  Which physical activity should children with Down syndrome avoid if they have atlantoaxial instability?

What are examples of autosomal dominant disorders?

Examples of autosomal dominant diseases include Huntington disease, neurofibromatosis, and polycystic kidney disease.

What is an example of an autosomal recessive disorder?

Examples of autosomal recessive disorders include cystic fibrosis, sickle cell anemia, and Tay-Sachs disease.