Syndactyly type 8

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Syndactyly type 8

ORPHA:2498Morphological anomaly

Also called Fusion of metacarpals 4 and 5

What it is

A rare non-syndromic syndactyly characterized by unilateral or bilateral fusion of the 4th and 5th metacarpals with no other associated abnormalities. Patients present shortened 4th and 5th metacarpals with excessive separation between their distal ends, resulting in marked ulnar deviation of the little finger and an inability to bring the 5th finger in parallel with the other fingers.

Key facts

Inheritance
Autosomal dominant, X-linked recessive
Classified as
Morphological anomaly

Gene

FGF16Disease-causing germline mutation(s)

ICD-10 codes

Q70.0filed under a broader ICD-10 category — shared with 8 other rare diseases

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Cross-references

GARD 3559MESH C564100MONDO 0010669OMIM 309630UMLS C1839728

Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.

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