Table 1: Some clues for the aetiopathogenesis of primary biliary cirrhosis (PBC) are provided by family studies.

References

Genes
(a) High incidence of mother-daughter pairs, and sister-sister pairs[1019]
(b) Increased incidence in PBC rates in families of PBC patients[1014]
(c) Similar AMA reactivity profiles shared among affected relatives[12]
(d) HLA DR8, the allele associated with susceptibility to PBC is found in familial cases[12, 20]
(e) Increased incidence of autoimmunity in PBC patients and their families[13, 21, 22]
(f) Identification of non-HLA genes with increased incidence among PBC patients (e.g., STAT4, CTLA4)[2325]
(g) Increased concordance among monozygotic but not dizygotic twins[26]

Environment
(a) Husband and wife with PBC (also shared same environment in childhood)[27]
(b) Three unrelated females who shared same work environment developed PBC[27]
(c) Women and daughter-in-law developed PBC[27]

Combined/Undifferentiated Genes and Environment
(a) Two unrelated women sharing same environment as well as HLA and AMA patterns developed PBC[20]
(b) Five of ten siblings in the same family developed PBC, two were asymptomatic but AMA positive, three AMA negative and asymptomatic[27]
(c) Mother-daughter-close family friend developed PBC[28]

A thorough list of studies reporting familial PBC in support of the role of genes and/or the environment in the pathogenesis of the disease is discussed in the main text, with the references in this table being a small representation.