The<unk>  is due to restricted ability for certain organs to grow due to severe oligohydramnios. In one study, the causes leading to<unk>  were bilateral renal agenesis in 21.25% of cases; cystic dysplasia in 47.5%; obstructive uropathy in 25%; and others in 5.25%. Bilateral renal agenesis Bilateral renal agenesis has been estimated to occur at a frequency of approximately 1:4000 to 1:8000 fetuses and neonates. However, recent analysis has estimated that the condition may occur at a much greater frequency. The condition has been reported to occur twice as commonly in males as in females, suggesting that certain genes of the Y chromosome may act as modifiers. However, no candidate genes on the Y chromosome have yet been identified. BRA appears to have a predominantly genetic etiology and many cases represent the most severe manifestation of an autosomal dominant condition with incomplete penetrance and variable expressivity. There are several genetic pathways that could result in this condition. In 2017 researchers identified heritable autosomal dominant mutations in the gene GREB1L in two unrelated families as being the cause of both BRA and URA utilizing Exome<unk> ng and direct<unk>  analysis. This is the first reported genetic lesion implicated in the activation of Retinoic Acid Receptor (RAR) Targets that has been associated with renal agenesis in humans. The majority of other possible candidate genetic pathways are autosomal recessive in nature and do not coincide with the frequency or penetrance at which BRA typically occurs in the human population. Additionally, candidate genetic pathways would be expected to involve genes expressed in the developing urogenital system (UGS). Often, these same genes and/or pathways of interacting genes are also expressed in the developing UGS as well as the central nervous system (CNS), gut, lung, limbs, and eyes.
Potter sequence
Lethal congenital contracture syndrome
Stafne defect
Crista dividens
Jordans' anomaly
Philadelphia basement kidnapping
Renal dysplasia-limb defects syndrome
Crisscross heart