Bartter Syndrome, Type 4A (BSND)
Bartter syndrome, type 4A is an autosomal recessive disorder caused by pathogenic variants in the gene BSND. This pan-ethnic disease is associated with life-threatening health problems present in utero or shortly after birth, including polyhydramnios, which increases the risk for premature birth, failure to thrive, constipation, dehydration, bone weakness, and hardening of kidney tissues. In addition, patients can experience muscle weakness and cramping as well as hearing loss and intellectual disability. With treatment available, life expectancy is not reduced. No genotype-phenotype correlation has been reported.
For information about carrier frequency and residual risk, please see the residual risk table.