nephronophthisis 12

Nephronophthisis 12 (NPHP12) is a rare genetic disorder that affects the kidneys and other parts of the body.

Characteristics of NPHP12

• Kidney disease: NPHP12 is characterized by chronic tubulointerstitial nephritis, cystic renal disease, and reduced renal concentrating ability [1].
• Cerebellar ataxia: Individuals with NPHP12 often experience cerebellar ataxia, which affects coordination and balance [5].
• Oculomotor apraxia: This condition is also associated with oculomotor apraxia, a rare disorder that affects eye movement [5].
• Hypotonia: People with NPHP12 may experience hypotonia, or low muscle tone [5].
• Neonatal breathing abnormalities: Some individuals with NPHP12 may have breathing difficulties at birth [5].
• Psychomotor delay: This condition can also lead to psychomotor delay, which affects cognitive and motor development [5].

Genetic cause

Nephronophthisis 12 is caused by mutations in the TTC21B gene on chromosome 2q24 [3]. This genetic mutation leads to the development of NPHP12.

Other information

• NPHP12 is an autosomal recessive disorder, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition [6].
• The disorder inevitably leads to end-stage kidney disease [8].

References:

[1] - Characterized by reduced renal concentrating ability, chronic tubulointerstitial nephritis, cystic renal disease, ...

[3] - Nephronophthisis-12 (NPHP12) is caused by homozygous or compound heterozygous mutation in the TTC21B gene (612014) on chromosome 2q24.

[5] - Nephronophthisis 12 is a disorder characterized by cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities, and psychomotor delay.

[6] - An autosomal recessive disorder resulting in end-stage renal disease. It is a progressive tubulo-interstitial kidney disorder histologically characterized ...

[8] - Nephronophthisis is an autosomal recessive tubulointerstitial nephropathy in which cysts often develop. It inevitably leads to end-stage kidney disease.

Early Signs and Symptoms of Nephronophthisis

Nephronophthisis often presents insidiously, with non-specific symptoms that may be easily overlooked. Early signs include:

• Increased thirst
• Excessive urination (polyuria)
• General fatigue

These symptoms result from the kidney's impaired ability to concentrate urine, leading to fluid and electrolyte imbalances.

Additional Symptoms

As the disease progresses, other symptoms may appear, including:

• Anemia
• Metabolic acidosis
• Nausea
• Vomiting
• Uremic gastritis
• Growth retardation

These symptoms can vary in severity and may not be present in all individuals with nephronophthisis.

Age of Onset

Symptoms of nephronophthisis may start to appear at a variety of ages, ranging from infancy to adulthood. The age of onset can differ between individuals and may depend on the specific genetic mutation causing the disease.

Citations: * [11] - Increased thirst, excessive urination (polyuria), and general fatigue are early signs of nephronophthisis. * [12] - Symptoms of nephronophthisis may start to appear at a variety of ages. * [13] - Anemia, metabolic acidosis, nausea, vomiting, uremic gastritis, and growth retardation are additional symptoms of nephronophthisis.

Nephronophthisis 12 (NPHP12) is a genetic disorder that affects the kidneys, and diagnostic tests play a crucial role in its diagnosis.

Genetic Testing

Genetic testing is considered the gold standard for diagnosing NPHP12. A positive genetic test can confirm the presence of the disease-causing gene mutation [7]. The genetic test assesses the TTC21B gene, which is associated with NPHP12 [8].

Renal Biopsy

A renal biopsy may also be performed to diagnose NPHP12. However, this invasive procedure is typically reserved for cases where genetic testing is inconclusive or not feasible [9].

Other Diagnostic Tests

While not specific to NPHP12, other diagnostic tests may be conducted as part of the investigative work-up:

• Blood tests for anemia, electrolyte imbalances, and metabolic acidosis
• Imaging studies (e.g., ultrasound) to assess kidney function and structure

It's essential to note that a definitive diagnosis of NPHP12 can only be made through genetic testing or renal biopsy.

References: [7] by F Luo · 2018 · Cited by 110 — The diagnosis of NPHP is suggested by clinical features and confirmed by a positive genetic test (Fig. 2). [8] Clinical Genetic Test offered by Intergen for conditions (1): Nephronophthisis 12; Testing genes (1): TTC21B (2q24.3); [9] by F Hildebrandt · 2001 · Cited by 54 — Molecular genetic testing offers the only method for definite diagnosis of NPH1 and avoids invasive diagnostic measures like renal biopsy.

Current Drug Therapy for Nephronophthisis

According to recent studies, the current drug therapy for nephronophthisis (NPH) is merely supportive, aimed at treating symptoms related to chronic kidney disease. This includes:

• Anemia treatment
• Hypertension management
• Growth retardation correction
• Other metabolic imbalances

However, it's worth noting that there is no specific therapy available for NPH. The management of the disease is focused on maintaining fluid and metabolic balance.

Promising Therapeutic Approaches

Recent research has identified promising therapeutic approaches for NPH, including:

• Ciliopathy-associated gene therapy
• Gene editing techniques
• Targeted drug therapies

These emerging treatments hold promise for improving outcomes in patients with NPH. However, further research is needed to fully understand their efficacy and safety.

References:

[8] Current drug therapy for NPH is merely supportive, aimed at treatment of anemia, hypertension, growth retardation and other symptoms related to chronic kidney disease. [9] Promising therapeutic approaches, including ciliopathy-associated gene therapy, gene editing techniques, or targeted drug therapies, can be effective in treating NPH.

Differential Diagnosis of Nephronophthisis

Nephronophthisis (NPHP) is a rare genetic disorder that causes end-stage kidney disease in children and young adults. When diagnosing NPHP, it's essential to consider other conditions that may present with similar symptoms. The differential diagnosis for NPHP includes:

• Autosomal Recessive Polycystic Kidney Disease (ARPKD): This is a genetic disorder characterized by the growth of numerous cysts in both kidneys. ARPKD can cause kidney failure and is often inherited in an autosomal recessive pattern [6].
• Early-Onset Autosomal Dominant Polycystic Kidney Disease (ADPKD): This is a genetic disorder that causes the growth of multiple cysts in the kidneys, leading to kidney failure. Early-onset ADPKD can present with similar symptoms to NPHP and is often inherited in an autosomal dominant pattern [6].
• Renal Hypodysplasia: This is a rare congenital disorder characterized by underdeveloped kidneys that may lead to kidney failure. Renal hypodysplasia can be associated with other genetic syndromes and should be considered in the differential diagnosis of NPHP [3].
• Medullary Cystic Kidney Disease (MCKD): This is a rare genetic disorder characterized by the growth of cysts in the medulla of the kidneys. MCKD can cause kidney failure and is often inherited in an autosomal recessive pattern [9].

It's essential to note that these conditions may present with similar symptoms, such as kidney failure, cystic changes in the kidneys, and end-stage renal disease. A comprehensive diagnostic workup, including genetic testing and imaging studies, is necessary to accurately diagnose NPHP and rule out other differential diagnoses.

References:

[3] - Context result 3 [6] - Context result 6 [9] - Context result 9