**Core Concept**
Neural tube defects (NTDs) such as spina bifida and anencephaly are congenital anomalies resulting from the incomplete closure of the neural tube during embryonic development. The etiology of NTDs is multifactorial, involving genetic, environmental, and nutritional factors.

**Why the Correct Answer is Right**
The inheritance pattern of NTDs is primarily sporadic, but there is a known genetic predisposition. The most significant genetic risk factor is the presence of a homozygous or heterozygous mutation in the MTHFR gene, which is involved in folate metabolism. Individuals with a family history of NTDs or a personal history of NTDs are more likely to have a genetic predisposition. Additionally, certain populations, such as those of Hispanic or South American descent, are at higher risk due to genetic factors.

**Why Each Wrong Option is Incorrect**
**Option A:** While some genetic syndromes, such as Meckel-Gruber syndrome, can increase the risk of NTDs, they are not the primary inheritance pattern.
**Option B:** There is no strong evidence to support an autosomal dominant inheritance pattern for NTDs.
**Option C:** While environmental and nutritional factors, such as folic acid deficiency, can contribute to the development of NTDs, they do not explain the inheritance pattern.

**Clinical Pearl / High-Yield Fact**
NTDs are a classic example of a multifactorial disorder, where both genetic and environmental factors interact to increase the risk of disease. Pregnant women at high risk of NTDs should be counseled on the importance of folic acid supplementation and genetic testing for MTHFR mutations.

**Correct Answer:** D.