Is Anencephaly hereditary?

Anencephaly is a serious birth defect that affects the development of the brain and skull in babies. It is characterized by the absence of a major portion of the brain, skull, and scalp. Babies born with anencephaly are usually missing the forebrain, which is responsible for critical functions such as thinking, hearing, vision, and coordination.

When it comes to the hereditary nature of anencephaly, it is important to understand that most cases of anencephaly are not inherited. The condition is typically caused by a combination of genetic and environmental factors. In fact, the majority of cases are considered sporadic, meaning they occur by chance and are not passed down from parents to their children.

However, there are rare instances where anencephaly can have a hereditary component. These cases are known as familial anencephaly. Familial anencephaly occurs when there is a specific genetic mutation or abnormality that is passed down through generations within a family.

One example of a genetic abnormality associated with familial anencephaly is a mutation in the PTCH1 gene. This gene is involved in the development of various body tissues, including the brain and skull. Mutations in the PTCH1 gene can disrupt normal development, leading to an increased risk of anencephaly in affected individuals.

It is important to note that familial anencephaly is extremely rare, and the vast majority of cases are sporadic. If a family has a history of anencephaly or other neural tube defects, it is recommended to consult with a genetic counselor or healthcare provider for a thorough evaluation and appropriate genetic testing.

While the hereditary component of anencephaly is limited, there are certain modifiable risk factors that can increase the chances of having a baby with this condition. These include:

• Folate deficiency: Lack of sufficient folic acid (a B vitamin) before and during early pregnancy can increase the risk of neural tube defects, including anencephaly. It is recommended for women of childbearing age to take a daily folic acid supplement to reduce this risk.


• Maternal diabetes: Poorly controlled diabetes during pregnancy can increase the risk of various birth defects, including anencephaly. Maintaining good control of blood sugar levels is crucial for reducing the risk.


• Exposure to certain medications and chemicals: Some medications and chemicals, such as certain anti-seizure medications and pesticides, have been associated with an increased risk of anencephaly. It is important to discuss any potential risks with a healthcare provider.

In conclusion, anencephaly is primarily a sporadic birth defect, meaning it is usually not inherited. However, there are rare cases of familial anencephaly associated with specific genetic mutations. It is important to address modifiable risk factors and consult with healthcare professionals for appropriate guidance and support.