sickle cell disorders are autosomal recessive conditions. In these conditions if the child inherited one copy of the gene, e.g. one copy of the gene variant that leads to change in the haemoglobin structure, the child will be a healthy carriers. However if the child inherits 2 copies of the gene variant (one copy from each parent) they can have the disease.
when only one partner carries a gene variant, he or she can pass on to a child either the usual gene or the gene variant. Each child therefore has a 1 in 2 (50%) chance of inheriting the variant and being a healthy carrier. None of the children can have a serious haemoglobin disorder. Each child also has a 50% chance of carrying the usual gene. Healthy carriers can pass on haemoglobin gene variants for many generations, without anyone realising that a variant is "in the family".
when both partners carry a gene variant, each can pass on to a child either the usual gene or the gene variant. There are four possible combinations of genes: At each conception there is a 25% (1 in 4) probability of a child with usual haemoglobin, a 50% (1 in 2) probability of a healthy carrier, and a 25% (1 in 4) probability of a inheriting 2 copies of the gene variant leading to a child with a sickle cell disorder
Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.