Yes, some types of anemia are due to inherited or genetic defects. Sickle cell anemia occurs most frequently in people of African, African-American, and Mediterranean descent. Thalassemia (or Cooley's anemia) is found in people of Mediterranean and Southeast Asian descent. These types of anemia are extremely common. Another inherited anemia is Fanconi anemia, but this is very rare.

Anemia results when there is not enough iron in the blood to carry oxygen to all parts of the body. Baby and toddlers, pregnant and menstruating women, and people who have lost blood need more iron.

The symptoms of anemia can include headache, fatigue, weakness, difficulty in thinking. With severe anemia, other symptoms, such as shortness of breath and rapid heartbeat, may be experienced.

Genetics may play a role in PMDD. Studies have shown that identical twins are more likely to share the disorder (93%) than non-identical (fraternal) twins (44%), and daughters of mothers with PMDD are more likely to have it themselves. However, no specific genes have been identified to account for PMDD. It is best to simply say that genetics may put a woman at greater risk for developing the disorder.

There is a genetic factor in the development of allergic disease. If one parent has allergic disease, the estimated risk of a child to develop allergies is 48%; the child's estimated risk grows to 70% if both parents have a history of allergies.

Research shows that ADHD tends to run in families, so there are likely to be genetic influences. Children who have ADHD usually have at least one close relative who also has ADHD. And at least one–third of all fathers who had ADHD in their youth have children with ADHD. Even more convincing of a possible genetic link is that when one twin of an identical twin pair has the disorder, the other is likely to have it too.

In humans, there are two modes of inheritance: autosomal dominant and autosomal recessive (with at least two, and possibly three different autosomal dominant forms of PKD caused by different genes at different loci). To date, only the autosomal dominant form has been identified in cats. To quote Dr. DiBartola, Professor of Veterinary Clinical Sciences at The Ohio State University College of Veterinary Medicine, and Co-Editor of the Journal of Veterinary Internal Medicine (one of the Dr.

Genetics is a complex subject, and The Foundation Fighting Blindness has prepared another booklet, "The Inheritance of Retinal Degenerations," to explain this topic in detail. (This can be ordered by using The Foundation's Publication Order Form.) There are so many different forms of RP, which fall within one of three standard inheritance patterns. Each type of inheritance will create a different pattern of affected and unaffected family members.

Most cases of PWS are attributed to a spontaneous genetic error that occurs at or near the time of conception for unknown reasons. In a very small percentage of cases (2 percent or less), a genetic mutation that does not affect the parent is passed on to the child, and in these families more than one child may be affected. A PWS-like disorder can also be acquired after birth if the hypothalamic portion of the brain is damaged through injury or surgery.

Most cases of epilepsy are not inherited, although some types have a genetic basis. Most of these types are easily controlled with medication. Epilepsy syndromes with a genetic basis: Primary Generalized Epilepsies, Benign Rolandic Epilepsy, Nocturnal Frontal Lobe Epilepsy, Familial Temporal Lobe Epilepsy, Benign Familial Neonatal Seizures and Benign Familial Infantile Spasms.

There are many factors that can influence the development of alcoholism. Genetics is one of these, and it is true that alcoholism tends to run in families. Some of the other factors that can influence a person to abuse alcohol are: There are no "rules" when it comes to alcohol abuse. A person with absolutely no family history of alcoholism can still become alcohol dependent. Or a person who has a family where every family member drinks may never develop alcoholism.

Only 3 to 5% of cases are inherited; the rest arise as an accident of chromosome arrangement during meiosis. For details, see my essay on the origin of trisomy 21 or Dr. Paul Benke's essay on the types of DS, and the risk and recurrence risk of DS. No. Down syndrome occurs at conception, so nothing in the pregnancy can cause Down syndrome to occur. As for prior to conception, the research all shows that drug or alcohol use does not increase the risk of having a child with DS.