What causes stubbed fingers as a birth defect?

There are multiple possible causes of stubby fingers (brachydactyly) as a birth defect:

Genetics: Some cases of brachydactyly are inherited, meaning they are passed down from parents to children through genes. There are several different genetic mutations that can cause brachydactyly, each leading to a different pattern of shortened fingers or toes.

Syndromic brachydactyly: Brachydactyly can also be associated with certain genetic syndromes, which are conditions caused by a combination of genetic and environmental factors. Some examples of syndromes that include brachydactyly include Down syndrome, Apert syndrome, and Pfeiffer syndrome.

Prenatal factors: Certain factors during pregnancy can also increase the risk of brachydactyly. For instance, exposure to certain chemicals, drugs, or infections during pregnancy can affect fetal development and lead to brachydactyly.

Developmental abnormalities: In some cases, brachydactyly can occur due to developmental abnormalities during early embryonic development. These abnormalities can affect the formation of the digits, resulting in shortened or underdeveloped fingers.

It's important to consult with a medical professional, such as a geneticist or pediatrician, to determine the specific cause of brachydactyly and receive appropriate medical advice and care.