eMedicine Specialties > Pediatrics: General Medicine > Nephrology
Oligomeganephronia
Updated: Jun 11, 2009
Introduction
Background
First described in 1962, oligomeganephronia is a type of renal hypoplasia that results from a quantitative defect of the renal parenchyma with a reduced number of nephrons. This condition differs histopathologically from simple hypoplasia, in which the renal mass is reduced but the number of nephrons is normal. Oligomeganephronia may occur as a sporadic defect or in association with numerous syndromes.
Pathophysiology
Oligomeganephronia results from arrested development of the metanephric blastema at 14-20 weeks' gestation, with subsequent hypertrophy of glomeruli and tubules in the kidney. This hypertrophy and hyperfiltration results in further nephron injury and sclerosis. Eventually, this progressive loss of nephrons leads to end-stage renal disease (ESRD).
Frequency
United States
Exact frequency of oligomeganephronia is difficult to determine. This condition cannot reliably be clinically distinguished from simple hypoplasia or hypoplasia with dysplasia unless the entire kidney is examined after nephrectomy or at autopsy. In the US Renal Data System, all hypoplasias and dysplasias are reported in a single category that accounts for 8.9% of pediatric ESRD. Incidence of end-stage renal failure due to all causes is 15 per 1 million population of persons younger than 20 years.
International
Oligomeganephronia has been primarily reported in France; however, it has also been described in other geographic areas.
Mortality/Morbidity
Oligomeganephronia is a progressive disorder, eventually resulting in chronic renal failure and ESRD. As with all such disorders, complications such as growth failure, metabolic bone disease, anemia, metabolic acidosis, and other disorders of fluid and electrolyte metabolism may occur.
Race
Renal hypoplasia and dysplasia may occur in people of any ethnic background. The US Renal Data System reports that 70.5% of children in this category are white.
Sex
No sex predominance has been reported, although the US Renal Data System shows a slight male predominance (61.3%) for the hypoplasia and dysplasia category.
Age
Oligomeganephronia may be suspected prenatally or at any time after birth.
Clinical
History
- In neonates, kidney disease is often suspected with spontaneous pneumothorax, feeding problems, or laboratory finding abnormalities.
- Oligomeganephronia is usually found in infants in their first year of life and presents with anorexia, vomiting, and failure to thrive.
- After the first year of life, individuals with oligomeganephronia most often present with short stature, polyuria and polydipsia, or proteinuria.
- This condition may be incidentally diagnosed when renal abnormalities are discovered during the course of another illness.
Physical
- Physical examination findings are frequently normal in children with oligomeganephronia.
- In neonates with oligomeganephronia, particular attention should be directed to diagnosis of associated syndromes, including branchiootorenal syndrome, acrorenal syndrome, and tapetoretinal dystrophia.
- Branchiootorenal syndrome is an autosomal dominant disorder that includes preauricular sinus or dimples, abnormally formed ears, branchial fistula, and hearing loss.
- Acrorenal syndromes may occur sporadically or in an autosomal recessive manner; these include ectrodactyly and urinary tract malformations.
- Tapetoretinal dystrophia occurs more frequently with nephronophthisis but has been described with oligomeganephronia.
Causes
- Developmental arrest of the metanephric blastema at 14-20 weeks' gestation causes oligomeganephronia.
- Although oligomeganephronia is associated with some genetic syndromes, most cases of oligomeganephronia are sporadic. However, mutations in the paired-box transcription factor, (PAX2) have been seen even in persons with nonsyndromic oligomeganephronia. Recently, mutations in the homeobox transcription factor (hepatocyte nuclear factor-1 b) have been described in association with oligomeganephronia. Interestingly, the heterozygous mutation may be associated with development of the kidney lesion.
- Vascular abnormalities and accidents have been associated with this type of renal hypoplasia. The cause of most oligomeganephronia cases is unknown.
- Transcription factor 2 (TCF2) is responsible for numerous malformations that involve the kidneys.1
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| References |
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References
Zaffanello M, Brugnara M, Franchini M, Fanos V. TCF2 gene mutation leads to nephro-urological defects of unequal severity: an open question. Med Sci Monit. Jun 2008;14(6):RA78-86. [Medline]. [Full Text].
[Guideline] Bush WH Jr, Choyke PL, Bluth RI, et al. Renal failure. ACR Appropriateness Criteria. 2005;[Full Text].
Bohn S, Thomas H, Turan G, et al. Distinct molecular and morphogenetic properties of mutations in the human HNF1beta gene that lead to defective kidney development. J Am Soc Nephrol. Aug 2003;14(8):2033-41. [Medline]. [Full Text].
Broyer M, Soto B, Gagnadoux MF, et al. Oligomeganephronic renal hypoplasia. Adv Nephrol Necker Hosp. 1997;26:47-63. [Medline].
Drukker A. Oligonephropathy: from a rare childhood disorder to a possible healthproblem in the adult. Isr Med Assoc J. Mar 2002;4(3):191-5. [Medline].
Janin-Mercier A, Palcoux JB, Gubler MC, et al. Oligomeganephronic renal hypoplasia with tapetoretinal degeneration. Report of one case with ultrastructural study of the renal biopsy. Virchows Arch A Pathol Anat Histopathol. 1985;407(4):477-83. [Medline].
Miltenyi M, Czeizel AE, Balogh L, Detre Z. Autosomal recessive acrorenal syndrome. Am J Med Genet. Jul 15 1992;43(5):789-90. [Medline].
Sagen JV, Bostad L, Njolstad PR, Sovik O. Enlarged nephrons and severe nondiabetic nephropathy in hepatocyte nuclear factor-1beta (HNF-1beta) mutation carriers. Kidney Int. Sep 2003;64(3):793-800. [Medline].
Salomon R, Tellier AL, Attie-Bitach T, et al. PAX2 mutations in oligomeganephronia. Kidney Int. Feb 2001;59(2):457-62. [Medline].
Van Acker KJ, Roodhooft AM, Melis K. Monozygotic twins non-concordant for oligomeganephronic renal hypoplasia: artery-vein placental shunting as a possible pathogenetic mechanism. Clin Nephrol. Mar 1986;25(3):165-8. [Medline].
Widdershoven J, Monnens L, Assmann K, Cremmers C. Renal disorders in the branchio-oto-renal syndrome. Helv Paediatr Acta. Dec 1983;38(5-6):513-22. [Medline].
Further Reading
Keywords
oligomeganephronic renal hypoplasia, oligomeganephronia, end-stage renal disease, ESRD, chronic renal failure, branchiootorenal syndrome, acrorenal syndrome, tapetoretinal dystrophia, renal atrophy, renal dysplasia, arrested development of the metanephric blastema, spontaneous pneumothorax, short stature, polyuria, polydipsia, proteinuria, acrorenal syndromes, treatment, diagnosis
