Autosomal recessive osteogenesis imperfecta (OI) accounts for 10% of all OI 
cases, and, currently, mutations in 10 genes (CRTAP, LEPRE1, PPIB, SERPINH1, 
FKBP10, SERPINF1, SP7, BMP1, TMEM38B, and WNT1) are known to be responsible for 
this form of the disease. PEDF is a secreted glycoprotein of the serpin 
superfamily that maintains bone homeostasis and regulates osteoid 
mineralization, and it is encoded by SERPINF1, currently associated with OI type 
VI (MIM 172860). Here, we report a consanguineous Brazilian family in which 
multiple individuals from at least 4 generations are affected with a severe form 
of OI, and we also report an unrelated individual from the same small city in 
Brazil with a similar but more severe phenotype. In both families the same 
homozygous SERPINF1 19-bp deletion was identified which is not known in the 
literature yet. We described intra- and interfamilial clinical and radiological 
phenotypic variability of OI type VI caused by the same homozygous SERPINF1 
19-bp deletion and suggest a founder effect. Furthermore, the SERPINF1 
genotypes/phenotypes reported so far in the literature are reviewed.