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Visceral Heterotaxy

Clinical Genetics Genomics Paediatrics


Heterotaxy (situs ambiguous) is a developmental condition characterized by randomization of the placement of visceral organs, including the heart, lungs, liver, spleen, and stomach. The organs are oriented randomly with respect to the left-right axis and with respect to one another.  Heterotaxy is a clinically and genetically heterogeneous disorder.

X-linked heterotaxy (HTX1) is caused by variants in the ZIC3 gene (Ware et al 2004 AJHG 74:93-105). In X-linked heterotaxy, abnormalities in the development of the midline are present. They can manifest as arhinencephalia, myelomeningocele, urological anomalies, hypertelorism, cleft palate and mostly, anomaly of the sacral spine and the anus.  Autosomal Visceral Heterotaxy type 2 (HTX2) is caused by heterozygous variants in the CFC1 gene (Bamford et al 2000 Nat Genet. 26: 365-369).

The laboratory participates in the European Molecular Genetics Quality Network (EMQN) sequencing scheme.

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