Band 3 Campinas: A Novel Splicing Mutation in the Band 3 Gene (AE1 ) Associated With Hereditary Spherocytosis, Hyperactivity of Na+/Li+ Countertransport and an Abnormal Renal Bicarbonate Handling

摘要: We have studied the molecular defect underlying band 3 deficiency in one family with hereditary spherocytosis using nonradioactive single strand conformation polimorphism of polymerase chain reaction (PCR) amplified genomic DNA AE1 gene. By direct sequencing, a base substitution splicing donor site intron 8 (position + 1G → T) was identified. The study cDNA showed skipping exon 8. This event is responsible for frameshift leading to premature stop codon 13 amino acids downstream. distal urinary acidification test by furosemide performed verify consequences α intercalated cortical collecting duct cells (αICCDC). found an increased basal bicarbonate excretion, associated pH and efficient acidification. also tested on Na+/H+ exchanger, measurement Na+/Li+ countertransport activity red blood cells. threefold sixfold patients compared controls. It possible that kidney leads decrease reabsorption HCO− αICCDC anion loss, which might be sodium-lithium activity.