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Disease Profile

Glomerulopathy with fibronectin deposits 2

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

GFND2; Glomerular nephritis familial with fibronectin deposits; Fibronectin glomerulopathy

Categories

Congenital and Genetic Diseases; Kidney and Urinary Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
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Orpha Number: 84090

Definition
A primary glomerular disease characterized by proteinuria, type IV renal tubular acidosis, microscopic hematuria and hypertension that may lead to end-stage renal failure in the second to sixth decade of life.

Epidemiology
Fibronectin glomerulopathy exact prevalence is unknown. Only 20 families and 25 sporadic cases have been described in the literature so far.

Clinical description
Fibronectin glomerulopathy may present at different ages, although mostly in adolescence or early adulthood, with typical features of a nephrotic syndrome including hypertension, which can be severe, and edema, which initially develops around the eyes and legs but with time may become generalized. Patients may also present with varying degrees of renal failure that progressively worsen over several years, reaching end stage renal disease in the second to sixth decade of life.

Etiology
Clustering of the disease within families indicates a genetic origin. In 40% of families, the disease is caused by heterozygous mutations in the FN1 gene (2q34) encoding fibronectin. Wholegenome linkage analysis in a large pedigree showed another disease locus on 1q32, however no specific candidate genes has been identified so far.

Diagnostic methods
Diagnosis rests on renal biopsy. Typical findings at light microscopy are enlarged glomeruli with deposits in the mesangium and subendothelial space, usually with scant immunoreactivity for immunoglobulins or complement factors. Electron microscopy reveals deposits mainly located in the subendothelial space but also in the subepithelial and intramembranous spaces. Homogeneous granular deposits dominate in most cases; in some an admixture of fibrils is observed. The most striking finding is the immunoreactivity of the glomerular deposits to fibronectin. Family history is supportive of the diagnosis.

Differential diagnosis
Differential diagnosis includes other chronic non-amyloid glomerulopathies with organized deposits including mixed cryoglobulinemia, fibrillary glomerulonephritis, immunotactoid glomerulopathy, collagen type III glomerulopathy, systemic lupus erythematosus, diabetes glomerulopathy and other non-specific collagen deposition diseases. It is difficult to discriminate fibronectin glomerulopathy from membranoproliferative glomerulonephritis at light microscopy examination.

Genetic counseling
Segregation with disease appearance in successive generations is consistent with an autosomal dominant pattern of inheritance with age-related penetrance. Genetic counseling should be proposed to individuals having the disease-causing mutation informing them that there is 50% risk of passing the mutation to offspring.

Management and treatment
There is no specific treatment for fibronectin glomerulopathy. Treatment of symptoms can include corticosteroids, diuretics and treatment for hypertension. Antiproteinuric and renoprotective treatment with ACE inhibitors or anti-AT1R antagonists could be of help to slow renal disease progression. More advanced cases of renal failure require renal dialysis or transplantation.

Prognosis
Prognosis is uncertain, in some cases the disease follows an indolent course and in others it leads to end stage renal disease and chronic renal failure in the second to sixth decade of life.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal glomerular mesangium morphology
0001966
Glomerulopathy
0100820
Hypertension
0000822
Hypoalbuminemia
Low blood albumin
0003073
Microscopic hematuria
Small amount of blood in urine
0002907
Nephrotic syndrome
0000100
Pedal edema
Fluid accumulation in lower limbs
Lower leg swelling

[ more ]

0010741
Proteinuria
High urine protein levels
Protein in urine

[ more ]

0000093
Renal insufficiency
Renal failure
Renal failure in adulthood

[ more ]

0000083
5%-29% of people have these symptoms
Cerebral hemorrhage
Bleeding in brain
0001342
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Generalized distal tubular acidosis
0004916
Renal cell carcinoma
Cancer starting in small tubes in kidneys
0005584
Slow progression
Signs and symptoms worsen slowly with time
0003677
Stage 5 chronic kidney disease
0003774

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Glomerulopathy with fibronectin deposits 2. This website is maintained by the National Library of Medicine.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Glomerulopathy with fibronectin deposits 2. Click on the link to view a sample search on this topic.