Clinodactaly
From Radipedia
Curving of the fifth finger toward the fourth finger.
Clinodactyly is a minor congenital malformation resulting from the a wedge shaped middle phalynx.
Clinodactyly may occur as an isolated finding in a person who is entirely normal or it may be found in association with other congenital malformations and, sometimes, mental retardation. It is a common component of Down (trisomy 21) syndrome and Klinefelter (XXY) syndrome.