Nephronophthisis in Finland: epidemiology and comparison of genetically classified subgroups

Abstract

Nephronophthisis -medullary cystic kidney disease is a progressive chronic tubulointerstitial nephritis leading to terminal renal failure. About two thirds of the patients with familial juvenile nephronophthisis, an autosomal recessive disease, have a homozygous deletion at the gene locus on 2q13. Through a nationwide search, 59 patients were ascertained in Finland. The incidence was 1:61 800 live births when calculated over a 20-year period. Of the patients, 17 came from four families showing dominant inheritance and 37 patients from 28 apparently recessive families when classified by family history, clinical features or presence of a deletion on 2q13. Two were considered as new dominant mutations; three sporadic patients could not be classified. The most significant difference between the patients with deletions, patients without deletions but having recessive family history, and patients belonging to families with dominant inheritance was the age at first symptoms, at the start of dialysis and at transplantation. These facts will be of help in determining the mode of inheritance of a sporadic patient without a deletion.

Nephronophthisis

“…The incidence of NPHP varies largely from 1:50,000 in Canada to approximately 1 in a million in the United States. In Finland the incidence of NPHP is reported as 1 in 61800 [5,7,14]. Finally, NPHP has also been diagnosed in adults with renal failure occurring later in life [15].…”

Nephronophthisis: A Genetically Diverse Ciliopathy

“…The median age of an affected child with ERF is 13 years [2]. The incidence of NPHP varies worldwide; it was previously identified to range from 1 in 50,000 to 1 in 900,000 [3–5]; however, these figures are likely to underrepresent the true frequency, since molecular testing has diagnosed NPHP in adults presenting with advanced chronic kidney disease (CKD) [6, 7]. The prevalence of NPHP amongst the paediatric population with ERF is 5% in the USA [2] and 6.5% in the UK [8, 9].…”

Nephronophthisis: A review of genotype–phenotype correlation

“…Nephronophthisis (NPHP), the most common monogenic cause of end‐stage renal disease (ESRD) during the first three decades of life, is responsible for 2.4%–15% of ESRD in this population. The estimated incidence varies from 1:50 000 live births in Finland to 1:1 000 000 in the United States . It is caused by mutations in many genes that encode nephrocystin protein, which is involved in the function of primary cilia, basal bodies, and centrosomes.…”