Tetradactyly

Tetradactyly is a condition characterized by the presence of four digits on the hands or feet, rather than the usual five. This condition can occur as an isolated anomaly or as part of a syndrome involving other anomalies. Tetradactyly can affect one limb (unilateral) or both limbs (bilateral), and it can vary in severity from partial to complete absence of the fifth digit.

Causes

The causes of tetradactyly are varied and can include genetic mutations, environmental factors, or a combination of both. In some cases, it is inherited in an autosomal dominant or autosomal recessive manner, depending on the specific gene mutation involved. Environmental factors that could potentially lead to tetradactyly include exposure to certain drugs or chemicals during pregnancy.

Classification

Tetradactyly can be classified into several types, depending on the digits involved and the presence of other anomalies. The most common classification divides tetradactyly into preaxial, postaxial, and central types. Preaxial tetradactyly affects the thumb side of the hand or the big toe side of the foot, postaxial tetradactyly affects the little finger side of the hand or the little toe side of the foot, and central tetradactyly involves the digits in the middle of the hand or foot.

Diagnosis

Diagnosis of tetradactyly is usually made through physical examination and imaging studies, such as X-rays, which can reveal the extent of the digit reduction and any associated skeletal anomalies. Genetic testing may also be performed to identify any underlying genetic causes or to determine the risk of the condition being passed on to offspring.

Treatment

The treatment of tetradactyly depends on the severity of the condition and the presence of any associated anomalies. In mild cases, no treatment may be necessary. In more severe cases, surgical intervention may be required to improve the function and appearance of the affected limbs. This can include procedures to reconstruct the digits, correct any associated deformities, or, in some cases, to add prosthetic digits.

Prognosis

The prognosis for individuals with tetradactyly varies depending on the severity of the condition and the presence of other anomalies. With appropriate treatment, most individuals are able to lead normal, active lives.

See also

• Polydactyly
• Syndactyly
• Oligodactyly