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. Author manuscript; available in PMC: 2021 Mar 1.
Published in final edited form as: Am J Med Genet C Semin Med Genet. 2020 Jan 30;184(1):90–96. doi: 10.1002/ajmg.c.31768

FIGURE 2.

FIGURE 2

Three phenotypic outcomes associated with mutations causing left–right patterning defects. Mutations causing left–right patterning defects can result in three laterality phenotypes. (a) An example of situs solitus, or the normal arrangement of visceral organ situs, in which the heart apex points toward the left, the stomach is left sided, there are three lung lobes visible on the right with two lung lobes visible on the left, and there are two liver lobes visible on the left and one liver lobe visible on the right. (b) An example of situs inversus totalis in which there is a mirror reversal of visceral organ situs and the heart apex points toward the right, the stomach is right sided, there are three lung lobes visible on the left with two lung lobes visible on the right, and there are two liver lobes visible on the right and one liver lobe visible on the left. (c) An example of heterotaxy in which there is randomization of visceral organ situs and the heart apex points toward the left, the stomach is right sided, there are three lung lobes visible on the left with two lung lobes visible on the right, and there are two liver lobes visible on the left and one liver lobe visible on the right. H, heart; L1–5, lung lobation; Liv1–3, liver lobation; stm, stomach. Scale bar represent 2.5 mm