The Greig Cephalopolysyndactyly Syndrome (GCPS) is a rare condition associated with a loss of function mutation in the GLI3 transcription factor gene. Biesecker reported criteria for the diagnosis of the condition. The author is from the National Human Genome Research Institute at NIH.


Chromosome affected: 7p13


Gene affected: GLI3 transcription factor


GCPS can be difficult to diagnose because its findings overlap with those of other conditions.


Criteria for definitive diagnosis - both of the following:

(1) all of the following phenotypic findings ("classic triad"):

(1a) preaxial polydactyly AND cutaneous syndactyly affecting at least 1 limb

(1b) hypertelorism

(1c) macrocephaly

(2) one or both of the following:

(2a) mutation in GLI3 identified on molecular analysis

(2b) one or more family members who have been definitively diagnosed with GCPS AND an autosomal dominant pattern of inheritance



• Polydactyly = increased numbers of digits

• Cutaneous syndactyly = attachment between digits due to persistent skin webs


The presence of criterion 1 without 2 allows for presumptive diagnosis of GCPS.


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