Cleft hand is associated with number of syndromes, see table 2.

The cause of cleft hand lies, for what is known, partly in genetics.

Cleft hand can be present as an isolated difference.

The social and stigmatising aspects of a cleft hand require more attention.

Literature shows that cleft hand is described centuries ago.

Surgical treatment of the cleft hand is based on several indications:

Also, central polydactyly can be associated with syndactyly and cleft hand.

However, the genetic causes of cleft hand related to syndromes have more clarity.

The exact chromosomal defect in isolated cleft hand is not yet defined.

The first reference to what might be considered a cleft hand was by Ambroise Paré in 1575.

The inheritance of cleft hand is autosomal dominant and has a variable penetrance of 70%.

Cleft hand can be a spontaneous mutation during pregnancy (de novo mutation).

Sometimes, in families with cleft hand with good function, operation for cosmetic aspects are considered as marginal and choose not to be operated.

The cleft hand appears as a V-shaped cleft situated in the centre of the hand.

However, the first certain description of what we know as a cleft hand as we know it today is described in the closure 19th century.

The treatment of cleft hand is usually invasive and can differ each time because of the heterogeneity of the condition.

There are several classifications for cleft hand, but the most used classification is described by Manske and Halikis see table 3.

Table 4 shows the treatment of cleft hand divided into the classification of Manske and Halikis.

The classification in which typical and atypical cleft hand are described was mostly used for clinical aspects and is shown in table 1.

Some studies have postulated that polydactyly, syndactyly and cleft hand have the same teratogenic mechanism.

Cleft hand can appear unilateral or bilateral, and can appear isolated or associated with a syndrome.

Historically, a U-type cleft hand was also known as atypical cleft hand.

In vivo tests showed that limb anomalies were found alone or in combination with cleft hand when they were given Myleran.

Cleft hand, also known as split hand, is a rare form of a congenital disorder in which the development of the hand is disturbed.

Polydactyly, syndactyly and cleft hand can occur within the same hand, therefore some investigators suggest that these entities occur from the same machanism.