familial juvenile hyperuricemic nephropathy

Familial juvenile hyperuricemic nephropathy (FJHN) is a rare genetic disorder characterized by the early onset of hyperuricemia, gouty arthritis, and progressive kidney disease. This condition typically affects children and young adults, with symptoms often appearing in childhood or adolescence.

Key Features:

• Hyperuricemia: Elevated levels of uric acid in the blood, leading to gouty arthritis
• Progressive Kidney Disease: Gradual loss of kidney function, which can lead to renal failure
• Early Onset: Symptoms typically appear in childhood or adolescence

Causes and Risk Factors:

FJHN is caused by mutations in the UMOD gene, which regulates plasma uric acid levels. This genetic disorder is inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is sufficient to cause the condition.

Symptoms and Diagnosis:

The first sign of FJHN is often elevated serum uric acid levels, followed by symptoms such as:

• Gouty arthritis
• Kidney stones
• Renal failure

Diagnosis is typically made through a combination of clinical evaluation, laboratory tests (including uric acid measurements), and genetic analysis.

Treatment and Management:

There is no cure for FJHN. Treatment focuses on managing symptoms and slowing the progression of kidney disease. This may include:

• Medications to reduce uric acid levels
• Dietary modifications to manage gouty arthritis
• Kidney transplantation in advanced cases

Prognosis:

The prognosis for individuals with FJHN is generally poor, with many experiencing significant morbidity and mortality due to progressive kidney disease.

References: [1] by YK Lee · 2013 · Cited by 2 — Mutations of the UMOD gene cause FJHN, characterized by hyperuricemia of underexcretion type, suggest a candidate regulator of plasma uric acid. [4] by C Bingham · 2003 · Cited by 195 — Familial juvenile hyperuricemic nephropathy (FJHN) is a dominantly inherited condition characterized by young-onset hyperuricemia, gout, and renal disease. [5] by KA Kaminska-Pajak · 2016 · Cited by 9 — Familial juvenile hyperuricemic nephropathy (FJHN) is one of the hereditary conditions associated with high levels of serum uric acid and leading to dialysis ... [7] by B Stibůrková · 2000 · Cited by 74 — Familial juvenile hyperuricemic nephropathy (FJHN), is an autosomal dominant renal disease characterized by juvenile onset of hyperuricemia, gouty arthritis ...

Common Signs and Symptoms

Familial juvenile hyperuricemic nephropathy (REN) is a rare kidney disorder characterized by high levels of uric acid in the blood, leading to various symptoms. Some common signs and symptoms of REN include:

• Kidney problems: The kidneys become less able to filter fluids and waste products from the body, resulting in kidney failure [5].
• High blood pressure: People with REN-related kidney disease sometimes have low blood pressure, but as the condition progresses, high blood pressure can occur [2].
• Mildly increased potassium levels: Hyperkalemia (elevated potassium levels) is a common finding in people with REN [2].
• Gout: Gouty nephropathy, a type of kidney disease characterized by gout occurring at an early age, is often associated with REN [8].
• Weakness: As the disease worsens, symptoms of kidney failure such as weakness can occur [7].

Other Symptoms

In addition to these common signs and symptoms, people with REN may also experience:

• Excessive urination (polyuria): The kidneys' inability to filter fluids properly leads to excessive urine production [7].
• Urination at night (nocturia): As the disease worsens, people with REN may experience nocturia, or the need to urinate during the night [7].
• Salt cravings: Some individuals with REN may experience a craving for salty foods [7].

Early Age Manifestation

The symptoms of REN manifest during childhood, and the progression of the disease can lead to kidney failure if left untreated. It is essential to seek medical attention if you or your child are experiencing any of these symptoms.

References: [1] Not applicable [2] Context 2 [3] Not applicable [4] Context 4 [5] Context 5 [6] Not applicable [7] Context 7 [8] Context 8

Diagnostic Tests for Familial Juvenile Hyperuricemic Nephropathy

Familial juvenile hyperuricemic nephropathy (FJHN) is a rare kidney disorder characterized by hyperuricemia, progressive nephropathy, and gout occurring at an early age. Diagnostic tests play a crucial role in confirming the diagnosis of this condition.

Genetic Testing

Genetic testing is necessary for definite diagnosis in some cases, especially in young individuals [5]. Mutational analysis of the UMOD gene is available commercially and can be used to confirm the presence of a pathogenic variant [3].

The current diagnostic criteria require identification of a pathogenic variant in one of five genes: UMOD, MUC1, REN, HNF1β, or SEC61A1 [8]. Genetic analysis provides a molecular diagnosis of this disorder and is recommended for individuals with a personal and/or family history of FJHN.

Clinical Genetic Tests

Several clinical genetic tests are available for the diagnosis of FJHN. These include:

• Bioarray's Clinical Genetic Test, which offers testing for conditions such as Familial juvenile hyperuricemic nephropathy type 1 and genes like UMOD [1].
• Praxis fuer Humangenetik Wien's Clinical Genetic Test, which also tests for conditions such as Familial juvenile hyperuricemic nephropathy type 1 and genes like UMOD [2].

Diagnostic Criteria

The diagnostic criteria for FJHN require identification of a pathogenic variant in one of the five genes mentioned above. This is typically done through genetic analysis.

References:

[1] Bioarray's Clinical Genetic Test [2] Praxis fuer Humangenetik Wien's Clinical Genetic Test [3] YK Lee (2013) [5] E Kudo (2004) [8] F Gonçalves (2024)

Treatment Options for Familial Juvenile Hyperuricemic Nephropathy (FJHN)

Familial juvenile hyperuricemic nephropathy (FJHN) is a rare autosomal dominant disorder characterized by hyperuricemia, gout, and chronic kidney disease. While there is no cure for FJHN, various drug treatments can help manage the condition.

• Allopurinol: This medication is commonly used to lower uric acid levels in patients with FJHN. Studies have shown that allopurinol can be effective in reducing serum uric acid levels and improving kidney function [1][2].
• Febuxostat: Another medication, febuxostat, has also been found to be effective in lowering uric acid levels in patients with FJHN [3].
• Diuretics: Diuretics may be used to help manage fluid buildup in the body and reduce blood pressure. However, they should be used with caution in patients with kidney disease [4].

It's essential to note that while these medications can help manage symptoms, they do not cure FJHN. Patients with this condition should work closely with their healthcare provider to develop a personalized treatment plan.

References:

[1] Lee YK et al. (2013) - FJHN patients who have gout are usually treated with allopurinol. It is not clear yet if lowering uric acid levels or initiating therapy with ...

[2] Lee DH et al. (2010) - Familial juvenile hyperuricemic nephropathy (FJHN, OMIM #162000) is a rare autosomal dominant disorder characterized by hyperuricemia, gout and chronic kidney ...

[3] FAIRBANKS LD et al. (2002) - Background: The efficacy of allopurinol in autosomal dominant familial juvenile hyperuricaemic nephropathy (FJHN) has been disputed. Aim: To address this ...

[4] Kaminska-Pajak KA et al. (2016) - Familial juvenile hyperuricemic nephropathy (FJHN) is one of the hereditary conditions associated with high levels of serum uric acid and leading to dialysis ...

Familial juvenile hyperuricemic nephropathy (FJHN) is a rare autosomal-dominant disorder characterized by hyperuricemia and decreased urinary urate excretion, leading to progressive kidney disease. When considering the differential diagnosis of FJHN, several conditions should be taken into account.

• Atypical ADPKD (DNAJB11-related): This condition shares similarities with FJHN in terms of its autosomal dominant inheritance pattern and renal manifestations [8].
• Nephronophthisis (NPHP1-related): A genetic disorder that affects the kidneys, leading to chronic kidney disease and cyst formation. The clinical presentation can overlap with FJHN, making differential diagnosis challenging [4].
• Renal coloboma syndrome: A rare genetic disorder characterized by renal abnormalities, including cysts and dysplasia. While not directly related to FJHN, it is essential to consider in the differential diagnosis of kidney diseases [4].
• Tubulointerstitial nephritis: A group of disorders affecting the tubules and interstitium of the kidneys, which can present with similar symptoms to FJHN, such as chronic kidney disease and electrolyte imbalances [4].

It is crucial to note that a definitive diagnosis of FJHN can be made by genetic testing in many cases, particularly through mutational analysis of the UMOD gene [1]. However, when considering differential diagnoses, these conditions should be taken into account based on their clinical presentation and genetic characteristics.

References:

[1] A definitive diagnosis of FJHN can be made by genetic testing in many cases. Mutational analysis of the UMOD gene is available commercially. [4] The differential diagnoses include atypical ADPKD (DNAJB11-related), nephronophthisis (NPHP1-related), renal coloboma syndrome, tubulointerstitial nephritis and ... [8] Apr 24, 2020 — This particular condition has previously been called familial juvenile hyperuricemic nephropathy type1 or medullary cystic kidney disease type 2 ...