congenital stationary night blindness autosomal dominant 2

Congenital Stationary Night Blindness Autosomal Dominant 2 (CSNBAD2)

Congenital stationary night blindness autosomal dominant 2, also known as CSNBAD2, is a rare genetic disorder that affects the retina and causes night blindness. This condition is inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is enough to cause the disease.

Key Features:

• Night Blindness: People with CSNBAD2 have difficulty seeing and distinguishing objects in low light conditions.
• Non-Progressive: The condition is non-progressive, meaning that it does not worsen over time.
• Genetic Cause: Mutations in the PDE6B gene on chromosome 4p16 are responsible for this condition.

Other Information:

• CSNBAD2 is one of three congenital nightblindness disorders with autosomal dominant inheritance (1, 14).
• The condition affects the rod cells in the retina, which are responsible for detecting light and color.
• Diagnosis relies on full-field electroretinograms (ERG) and genetic testing to confirm the presence of the mutated gene.

References:

• [2] - Congenital stationary night blindness autosomal dominant 2 is a non-progressive retinal disorder with impaired night vision, often accompanied by nystagmus.
• [14] - CSNBAD2, or type AD2, is one of three congenital nightblindness disorders with autosomal dominant inheritance. It results from mutations in the PDE6B gene (4p16.3) encoding a subunit of rod cGMP-specific phosphodiesterase.

Symptoms of Congenital Stationary Night Blindness Autosomal Dominant 2 (CSNBAD2)

Congenital stationary night blindness autosomal dominant 2 (CSNBAD2) is a rare genetic disorder that affects the retina, leading to impaired vision in low light conditions. The symptoms of CSNBAD2 are similar to those of other forms of congenital stationary night blindness.

• Night Blindness: People with CSNBAD2 have difficulty seeing and distinguishing objects in low light (night blindness). This is because the photoreceptors in their retina do not function properly, making it hard for them to adapt to low-light conditions.
• Reduced Visual Acuity: Individuals with CSNBAD2 may experience reduced visual acuity, which can range from 20/30 to 20/200. This means that they may have difficulty seeing objects clearly, even in bright light.
• Myopia (Nearsightedness): Many people with CSNBAD2 develop myopia, which is a condition where close objects are seen clearly but distant objects appear blurry.
• Normal Color Vision: Unlike some other forms of congenital stationary night blindness, individuals with CSNBAD2 typically have normal color vision.

Other Possible Symptoms

While not universal, some people with CSNBAD2 may also experience:

• Nystagmus: Involuntary movements of the eyes
• Strabismus: Misalignment of the eyes
• Increased Sensitivity to Light (Photophobia): Some individuals may be more sensitive to light than others

Genetic Basis

CSNBAD2 is caused by mutations in the PDE6B gene, which encodes a subunit of rod cGMP-specific phosphodiesterase. This enzyme plays a crucial role in the phototransduction pathway, and its dysfunction leads to impaired vision in low light conditions.

References:

• [11] Mutations in the RHO, GNAT1, or PDE6B gene cause autosomal dominant congenital stationary night blindness.
• [12] CSNBAD2 is one of three congenital nightblindness disorders with autosomal dominant inheritance, resulting from mutations in the PDE6B gene.

Diagnostic Tests for Congenital Stationary Night Blindness Autosomal Dominant 2

Congenital stationary night blindness (CSNB) autosomal dominant 2 is a rare genetic disorder that affects the retina. Diagnosing this condition can be challenging, but several diagnostic tests are available to confirm the presence of CSNBAD2.

Electroretinography (ERG): This test measures the electrical activity of the retina in response to light stimuli. In individuals with CSNBAD2, ERG results typically show a selective loss of the b-wave, which is indicative of rod system dysfunction [5].

Genetic Testing: Genetic testing can identify mutations in the PDE6B gene, which is associated with CSNBAD2. This test involves analyzing DNA samples from affected individuals to detect pathogenic variants [14]. Sequence analysis of the entire coding region and Next-Generation (NGS)/Massively parallel sequencing (MPS) are also used for genetic diagnosis [13].

Clinical Molecular Genetics Test: A clinical molecular genetics test, such as the one offered by CGC Genetics, can be performed to confirm the presence of CSNBAD2. This test involves sequence analysis of the entire coding region and NGS/MPS [13].

Other Diagnostic Tests: While not specific to CSNBAD2, other diagnostic tests like full-field electroretinograms (ERG) and clinical genetic tests may also be used in conjunction with ERG and genetic testing to confirm the diagnosis.

It's essential to consult a medical professional for accurate diagnosis and treatment of CSNBAD2. They will determine the best course of action based on individual circumstances.

References:

[5] Congenital stationary night blindness (CSNB) is a group of genetically determined, largely non-progressive retinal disorders characterised by rod system dysfunction. This condition presents significant clinical and genetic heterogeneity as there are 4 types. 1,2 Diagnosis relies on full-field electroretinograms (ERG) and genetic testing to confirm the presence of CSNBAD2.

[13] Clinical Molecular Genetics test for Congenital stationary night blindness autosomal dominant 2 and using Sequence analysis of the entire coding region, Next-Generation (NGS)/Massively parallel sequencing (MPS) offered by CGC Genetics.

[14] Any congenital stationary night blindness in which the cause of the disease is a mutation in the PDE6B gene. Congenital stationary night blindness autosomal dominant 2 (CSNBAD2) MedGen UID: 361814 ... Diagnosis. A clinical and electrophysiological case study of a child with a novel frame shift mutation in the CACNA1F and missense variation of...

Unfortunately, there is no specific drug treatment for congenital stationary night blindness (CSNB) autosomal dominant type. However, I can provide some information on the current understanding and management of this condition.

Current Understanding

Congenital stationary night blindness (CSNB) is a group of inherited retinal diseases that affect the rod photoreceptors in the retina, leading to night blindness. The autosomal dominant form of CSNB is caused by mutations in genes such as RHO, GNAT1, and PDE6B.

Management

There is currently no specific treatment available for most forms of CSNB, including the autosomal dominant type. Management focuses on symptomatic relief and supportive care to improve quality of life.

• Visual aids: Patients may benefit from visual aids such as magnifying glasses or telescopes to enhance their vision.
• Low-vision therapy: Low-vision therapy can help patients adapt to their visual impairment and develop strategies for daily living.
• Genetic counseling: Genetic counseling is essential for families with a history of CSNB, as it can provide information on the risk of passing the condition to future generations.

Research

While there are no specific drug treatments available for CSNB autosomal dominant type, research is ongoing to explore potential therapeutic options. Gene therapy and other innovative approaches may hold promise for treating this condition in the future.

References:

• [1] Congenital stationary night blindness (CSNB) is a group of genetically determined, largely non-progressive retinal disorders characterised by rod system dysfunction. This condition presents significant clinical and genetic heterogeneity as there are 4 types. 1,2 Diagnosis relies on full-field electroretinograms (ERG) and genetic testing to confirm the diagnosis.
• [5] Congenital stationary night blindness (CSNB) is an inherited retinal disease (IRD) that causes night blindness in childhood with heterogeneous genetic, electrophysical, and clinical characteristics. The development of sequencing technologies and gene therapy have increased the ease and urgency of diagnosing IRDs.
• [9] Treatment for CSNB. There is currently no treatment available for most forms of CSNB. However, because the defect in fundus albipunctatus affects regeneration ...

The differential diagnosis for Congenital Stationary Night Blindness Autosomal Dominant 2 (CSNBAD2) involves distinguishing it from other causes of flecked retina and retinal disorders. Some possible conditions that may be considered in the differential diagnosis include:

• Other forms of congenital stationary night blindness, such as X-linked or autosomal recessive types
• Retinitis pigmentosa (RP), a group of genetic disorders affecting the retina's ability to respond to light
• Flecked retina, a condition characterized by small spots on the retina that can be caused by various factors, including genetics and age-related changes
• Other retinal disorders, such as cone-rod dystrophy or Leber congenital amaurosis

According to [3], diagnosis relies on full-field electroretinograms (ERG) and genetic testing to confirm the presence of CSNBAD2. Additionally, a clinical case study in [14] describes a child with a novel frame shift mutation in the CACNA1F gene and missense variation of the PDE6B gene, which is associated with CSNBAD2.

It's worth noting that the differential diagnosis for CSNBAD2 may also involve considering other conditions that can cause similar symptoms, such as night blindness or visual impairment. However, a thorough evaluation by an eye care professional, including a comprehensive medical history and physical examination, along with diagnostic tests like ERG and genetic testing, is essential to accurately diagnose CSNBAD2.

References: [3] Congenital stationary night blindness (CSNB) is a group of genetically determined, largely non-progressive retinal disorders characterised by rod system dysfunction. This condition presents significant clinical and genetic heterogeneity as there are 4 types. 1,2 Diagnosis relies on full-field electroretinograms (ERG) and genetic testing to ... [14] Any congenital stationary night blindness in which the cause of the disease is a mutation in the PDE6B gene. Congenital stationary night blindness autosomal dominant 2 (CSNBAD2) MedGen UID: 361814 ... Diagnosis. A clinical and electrophysiological case study of a child with a novel frame shift mutation in the CACNA1F and missense variation of ...