Clinodactyly is a medical term describing the curvature of a digit (a finger or toe) in the plane of the palm, most commonly the fifth finger (the "

little finger The little finger, or pinkie, also known as the baby finger, fifth digit, or pinky finger, is the most ulnar and smallest digit of the human hand, and next to the ring finger. Etymology The word "pinkie" is derived from the Dutch word ''p ...

") towards the adjacent fourth finger (the "

ring finger The ring finger, third finger, fourth finger, leech finger, or annulary is the fourth digit of the human hand, located between the middle finger and the little finger. Sometimes the term ring finger only refers to the fourth digit of a left-han ...

"). It is a fairly common isolated anomaly which often goes unnoticed, but also occurs in combination with other abnormalities in certain genetic

syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek language, Greek σύνδρομον, meaning "concurrence". When a sy ...

s. The term is from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

κλίνειν ' 'to bend' and δάκτυλος ' 'digit'.

Genetics

Clinodactyly is an autosomal dominant trait that has variable expressiveness and incomplete

penetrance Penetrance in genetics is the proportion of individuals carrying a particular variant (or allele) of a gene (the genotype) that also express an associated trait (the phenotype). In medical genetics, the penetrance of a disease-causing mutation is t ...

. Clinodactyly can be passed through inheritance and presents as either an isolated anomaly or a component manifestation of a genetic syndrome. Many syndromes are associated with clinodactyly, including those listed below. But the phenotype, by itself, is not a sensitive or specific diagnostic test for these syndromes (it is present in up to 18% of the normal population). *

Down syndrome Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual dis ...

Turner syndrome Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hair ...

* Aarskog syndrome *

Carpenter syndrome Carpenter syndrome, also called acrocephalopolysyndactyly type II, is an extremely rare autosomal recessive congenital disorder characterized by craniofacial malformations, obesity, syndactyly, and polydactyly. Acrocephalopolysyndactyly is a varia ...

Seckel syndrome Seckel syndrome, or microcephalic primordial dwarfism (also known as bird-headed dwarfism, Harper's syndrome, Virchow–Seckel dwarfism and bird-headed dwarf of Seckel) is an extremely rare congenital nanosomic disorder. Inheritance is autosomal ...

Cornelia de Lange syndrome Cornelia de Lange syndrome (CdLS) is a genetic disorder. People with this syndrome experience a range of physical, cognitive, and medical challenges ranging from mild to severe. The syndrome has a widely varied phenotype, meaning people with the sy ...

Orofaciodigital syndrome 1 Orofaciodigital syndrome 1 (OFD1), also called Papillon-League and Psaume syndrome, is an X-linked congenital disorder characterized by malformations of the face, oral cavity, and digits with polycystic kidney disease and variable involvement of t ...

13q deletion syndrome 13q deletion syndrome is a rare genetic disease caused by the deletion of some or all of the large arm of human chromosome 13. Depending upon the size and location of the deletion on chromosome 13, the physical and mental manifestations will vary. ...

XXYY syndrome XXYY syndrome is a sex chromosome anomaly in which males have 2 extra chromosomes, one X and one Y chromosome. Human cells usually contain two sex chromosomes, one from the mother and one from the father. Usually, females have two X chromosomes ( ...

Silver–Russell syndrome Silver–Russell syndrome (SRS), also called Silver–Russell dwarfism, is a rare congenital growth disorder. In the United States it is usually referred to as Russell–Silver syndrome (RSS), and Silver–Russell syndrome elsewhere. It is one of ...

* Andersen-Tawil syndrome *

Noonan syndrome Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored ...

* Ehlers–Danlos syndrome When identified prenatally, ''in conjunction with other features'' of Down syndrome, for example during

obstetric ultrasonography Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a stan ...

, it may be an indication for intrauterine sampling for fetal chromosome analysis.

Pathophysiology

Due to a developmental arrest, there is an abnormal alignment of the joint surfaces at either interphalangeal joint causing angulation in the plane of the palm. The finger may be slightly bent or have a very prominent bend.

Diagnosis

There is no consensus on what degree of angulation justifies a diagnosis; an incline between 15° and 30° is typical. A similar-sounding term,

camptodactyly Camptodactyly is a medical condition that causes one or more fingers or toes to be permanently bent. It involves fixed flexion deformity of the proximal interphalangeal joints. Camptodactyly can be caused by a genetic disorder. In that case, it ...

, is a fixed flexion deformity of a digit.

Management

Treatment is only necessary if the degree of curvature is sufficient to cause disability or if it causes emotional distress. Splinting does not routinely correct the deformity. Surgical treatments are closing wedge osteotomy, opening wedge osteotomy, and reversed wedge osteotomy. Radiographs of the fingers are useful in planning the surgical procedure. Severe clinodactyly may require soft tissue alterations to the digit such as release of skin, extensor tendon relocation, and collateral ligament advancement.

Epidemiology

Minor degrees of curvature are common. Reports of incidence vary between 1% and 19.5%.

References

External links

{{Congenital malformations and deformations of musculoskeletal system Human genetics Congenital disorders of musculoskeletal system