CLAPO, HHML and KTS are some of the PIK3CA-related overgrowth syndromes (PROS).

Chromosome: 3q26.32

Gene: PIK3CA (phosphoinositide-3 kinase)

Genetic alteration: somatic mutation with postzygotic mosaic gain-of-function


Inheritance: not known to be inherited


CLAPO = capillary malformation of the lower lip, lymphatic malformation, asymmetry and partial or generalized overgrowth:

(1) partial or generalized overgrowth of soft tissues and bone

(2) lower lip capillary malformation without progression

(3) lymphatic malformation of head, neck, and/or chest


HHML = hemihyperplasia multiple lipomatosis:

(1) asymmetric overgrowth of a body part of body segment, which may be static or slowly progressive

(2) multiple lipomas


KTS = Klippel-Trenaunay Syndrome:

(1) bone and/or soft tissue overgrowth in a unilateral limb

(2) digital enlargement

(3) low-flow venous or lymphatic malformation

(4) capillary malformation (port-wine nevus)

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