Which are the causes of Ectrodactyly?

Causes of Ectrodactyly

Ectrodactyly, also known as split hand/split foot malformation, is a rare congenital condition characterized by the abnormal development of the hands and/or feet. It is a limb malformation that affects the central rays of the limbs, resulting in the absence or fusion of fingers or toes. Ectrodactyly can occur as an isolated condition or as part of a syndrome.

Genetic Factors: The primary cause of ectrodactyly is genetic mutations. Several genes have been identified to play a role in the development of this condition. The most common form of ectrodactyly, known as autosomal dominant ectrodactyly (AD), is caused by mutations in the TP63 gene. TP63 is involved in the regulation of limb development and mutations in this gene disrupt the normal formation of fingers and toes.

Environmental Factors: While genetic factors are the main cause of ectrodactyly, certain environmental factors can also contribute to the development of this condition. Exposure to teratogenic substances during pregnancy, such as certain medications, chemicals, or infections, can increase the risk of limb malformations including ectrodactyly. Maternal smoking and alcohol consumption during pregnancy have also been associated with an increased risk of limb abnormalities.

Maternal Age: Advanced maternal age has been identified as a potential risk factor for ectrodactyly. Studies have shown that women who conceive at an older age, typically above 35 years, have a slightly higher risk of having a child with limb malformations, including ectrodactyly. However, the exact mechanism behind this association is not yet fully understood.

Chromosomal Abnormalities: In some cases, ectrodactyly can be associated with chromosomal abnormalities. Certain chromosomal disorders, such as monosomy 10p, trisomy 13, and trisomy 18, have been linked to the development of limb malformations including ectrodactyly. These chromosomal abnormalities disrupt the normal genetic and developmental processes, leading to limb defects.

Family History: Ectrodactyly can be inherited in an autosomal dominant or autosomal recessive manner. If a parent has ectrodactyly or carries a genetic mutation associated with this condition, there is a higher chance of passing it on to their children. However, it is important to note that not all cases of ectrodactyly have a family history, as some individuals may have spontaneous mutations.

Other Syndromes: Ectrodactyly can also occur as part of various syndromes or genetic disorders. For example, ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome is a rare genetic disorder characterized by the triad of ectrodactyly, ectodermal dysplasia (abnormalities in hair, teeth, and sweat glands), and cleft lip/palate. There are several other syndromes where ectrodactyly is one of the associated features.

Ectrodactyly is a complex condition with multiple causes, including genetic factors, environmental influences, maternal age, chromosomal abnormalities, family history, and associated syndromes. It is important to consult with a healthcare professional for a proper diagnosis, genetic counseling, and appropriate management of ectrodactyly.