Table 1.

Clinical and genetic subtypes of osteogenesis imperfect.

Group	Subtype	Genes	Inheritance	Mechanism
Group A	Type I	COL1A1 or COL1A2	AD	Defects in collagen synthesis, structure, or processing
	Type II	COL1A1 or COL1A2	AD
	Type III	COL1A1 or COL1A2	AD
	Type IV	COL1A1 or COL1A2	AD
	Type XIII	BMP1	AD
Group B	Type VII	CRTAP	AR	Post-translational modification of collagen
	Type VIII	LEPRE1	AR
	Type IX	PPB	AR
	Type XIV	TMEM38B	AR
Group C	X	SERPINH1	AR	Collagen folding or cross-linking
	XI	FKBP10	AR
	–	PLOD2	AR
	–	P4HB§	AD
Group D	V	IFTM5	AD	Defects in bone mineralization
	VI	SERPINF1	AR
Group E	XII	SP7	AR	Defects in osteoblast differentiation
	XV	WNT1	AR
	XVI	CREB3L1	AR

^§Mutations in P4HB have been associated with a Cole-Carpenter syndrome in which an OI-like phenotype occurs as part of a wider syndrome but recent reports indicate that P4HB mutations can also result in a mild OI phenotype.