Renal features of Bardet Biedl syndrome: A single center experience

Özet

Bardet Biedl syndrome (BBS), is a multisystemic disorder which is describedas a ciliopathy. BBS is a rare autosomal recessive disorder and 21 differentBBS genes have been defined to date. BBS is characterized with dysmorphicextremities, retinitis pigmentosa, obesity, hypogenitalism, intellectual disabililityand renal structural abnormalities. Renal symptoms in patients with BBS,are nonspecific and often undetected until end-stage renal disease. Here,we were reported 23 children with BBS (12 females, 11 males) with renalabnormalities from a single center and defined their features. Age at diagnosiswere very variable (2 days-16 years). Median age at diagnosis was 84 months.Mean follow-up period was 42 months. All 23 children had urinary tractabnormalities on renal ultrasonography. These abnormalities were polycysts(34.8%), hyperechogenic kidneys (34.8%), fetal lobulation (21.7%), hypoplasiaon at least one kidney (21.7%) and hydronephrosis in at least one kidney(17.4%). Vesicoureteral reflux and neurogenic bladder detected 11.1% and22.2% of patients who recieved a voiding cystourethrogram, respectively.Proteinuria was found in 39 % of patients. Hypertension was defined in 21.7%of patients. Six of 23 children (26%) in our cohort had proven mutationsin BBS genes. Five of them (83.3%) had homozygous mutations in BBS10gene and one of them had homozygous mutation in BBS2 gene. All of 23children had retinitis pigmentosa, twenty two of them (95.6%) had learningdisabilities/cognitive impairment and seventeen of them (82.6%) had obesity.Renal involvement is now accepted as a cardinal feature and the mostimportant factor causing mortality in BBS.