SNP Shot: Genomic Insights

Renal tubular dysgenesis (RTD) is a serious condition affecting kidney development before birth. The proximal tubules, essential kidney structures responsible for reabsorbing vital substances into the blood and filtering waste into urine, are either missing or poorly developed. The absence of functional proximal tubules prevents urine production (anuria).

Because fetal urine is a primary source of amniotic fluid, anuria results in reduced amniotic fluid levels (oligohydramnios). Amniotic fluid is crucial for fetal protection and the proper development of various organs, especially the lungs. Oligohydramnios can lead to Potter sequence, a cluster of abnormalities including characteristic facial features (flattened nose, large and low-set ears), extra skin folds, clubfeet, and underdeveloped lungs.

RTD also causes severe hypotension (low blood pressure). Additionally, some individuals with RTD have abnormal skull bone development, resulting in enlarged fontanelles (spaces between the skull bones).

Due to the severity of these complications, most infants with RTD die before or shortly after birth from respiratory failure. In rare cases, with medical intervention, survival into childhood is possible. While blood pressure may normalize, these individuals typically develop chronic kidney disease, a progressive decline in kidney function.

Inheritance:

RTD is inherited in an autosomal recessive manner. This means that an affected individual has inherited two copies of a mutated gene, one from each parent. The parents, while carrying one copy of the mutated gene each, usually do not exhibit any signs or symptoms of the condition.