Using a large prospective multicenter cohort (ChiLREN study group), a recent study examined 289 infants and identified three subtypes of biliary atresia (BA) enrolled in PROBE (Hepatology 2013; 58: 1724-31).
Previously, BA has been considered to have two presentations:
- Acquired/nonsyndromic ~90%
- Embryonic/syndromic ~10%
However, this study suggests the following:
- Group 1 -nonsyndromic, isolated BA. n=242 (84%)
- Group 2 -BA with major malformation but without laterality defect. n=17 (6%)
- Group 3 -syndromic, with laterality defect. n=30 (10%)
Group 3 BA defects included splenic abnormalities (eg. asplenia, polysplenia, right-sided spleen), cardiovascular anomalies (eg. dextrocardia, TAPVR, interrupted IVC) and gastrointestinal anomalies (eg. “abdominal heterotaxy,” malrotation, annular pancreas).
In contrast, Group 2 BA had frequent genitourinary problems (cystic kidney and hydronephrosis) along with different cardiovascular anomalies and gastrointestinal anomalies which included esophageal/duodenal/jejunal atresia and imperforate anus.
- The frequency of cardiac problems is particularly important to recognize as this could make differentiation from Alagille syndrome more difficult.
- One other interesting finding was the high incidence of autoimmunity in first-degree relatives of all BA groups (~44%).
Bottomline: there are at least 3 subtypes of BA.