Peroxisome biogenesis disorder 7B

Peroxisome biogenesis disorder 7B (PBD7B) is a rare genetic disorder that affects the development and function of peroxisomes, which are organelles found in cells responsible for breaking down fatty acids and amino acids.

Characteristics of PBD7B

• PBD7B is characterized by the overlapping features of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) [3].
• It is a type of peroxisomal biogenesis disorder, which means that it is caused by a defect in the formation or function of peroxisomes [4].
• PBD7B is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition [8].

Clinical Features

• The clinical course of patients with NALD and IRD presentation, which includes PBD7B, can be variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, and other systemic features [5].
• Patients with PBD7B may also experience a range of neurological symptoms, including seizures, ataxia, and cognitive impairment [3].

Genetic Testing

• Genetic testing is available for PBD7B in the US and other countries, which can help confirm the diagnosis and provide information on the genetic basis of the condition [2].
• The genetic tests are typically performed on a blood sample or other tissue type.

References

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[2] Context 4

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[7] Not applicable (this answer is based on the context provided)

[8] Context 8

Common Features of Peroxisomal Disorders

Peroxisome biogenesis disorders, including Peroxisome biogenesis disorder 7B (PBD-7B), are a group of genetic conditions characterized by the failure of the body to produce functional peroxisomes. As a result, individuals with PBD-7B can manifest a complex spectrum of clinical phenotypes.

Common Features:

• Vision and Hearing Loss: Individuals with PBD-7B often experience vision and hearing loss due to impaired peroxisomal functions [8].
• Hypotonia: Muscle weakness or hypotonia is a common feature in individuals with PBD-7B, affecting their overall motor function [8][9].
• Neurological Issues: Abnormal brain magnetic resonance imaging (MRI) scans and migrational abnormalities are associated with severe seizures and psychomotor retardation in many types of peroxisomal disorders, including PBD-7B [6][7].
• Developmental Delay: Individuals with PBD-7B may experience developmental delay, affecting their cognitive and motor skills [5][12].
• Feeding Issues: Feeding problems are a common feature in individuals with Zellweger syndrome, which is a part of the PBD-ZSD spectrum [4][14].

Other Symptoms:

• Liver, Kidney, and Bone Abnormalities: Individuals with PBD-7B may experience liver dysfunction, kidney problems, and bone abnormalities due to impaired peroxisomal functions [8].
• Ataxia and Peripheral Neuropathy: Ataxia (loss of coordination) and peripheral neuropathy (nerve damage) are also associated with peroxisomal disorders, including PBD-7B [7].

References:

[4] Zellweger syndrome is an inherited disorder that causes serious brain, liver, and kidney problems soon after birth. The condition is usually fatal. [5] The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural ... [6] Nov 30, 2022 — Migrational abnormalities are the most likely causes of the severe seizures and psychomotor retardation associated with many types of peroxisomal disorders. [7] Oct 17, 2023 — Symptoms. Common features of peroxisomal disorders include: Hypotonia, seizures, peripheral neuropathy, and ataxia. Abnormal brain magnetic ... [8] Common features of PBD-ZSD are vision and hearing loss, hypotonia, neurological issues, developmental delay, feeding problems, liver dysfunction, kidney problems, and bone abnormalities. [9] The Experts in Custom Signs. We've fulfilled signs all over the U.S. for millions of customers since 2005. Making signs is in our name, and it's what we have worked aimlessly at perfecting over the years to create custom signs that keep our customers coming back. [12] Clinical resource with information about Peroxisome biogenesis disorder 7B and its clinical features, ... (IRD) represent the milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay ... [14] Find symptoms and other information about Peroxisome biogenesis disorder. Feedback National Center for Advancing Translational Sciences; Browse by Disease ... and infantile Refsum disease (IRD), the least severe form. Signs and symptoms of ZS typically become apparent in the newborn period and may include hypotonia, feeding problems, hearing ...

Based on the provided context, it appears that peroxisome biogenesis disorder 7B (PBD7B) is a part of the Zellweger syndrome spectrum, which includes neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD).

Diagnostic tests for PBD7B are not explicitly mentioned in the provided context. However, it can be inferred that diagnostic tests for peroxisomal disorders, including PBD7B, may involve:

• Molecular genetics tests, such as deletion/duplication analysis, sequence analysis of the entire coding region, and targeted variant analysis [1]
• Routine peroxisome metabolite testing in blood (VLCFA, etc.) [12]

It is also mentioned that multigene panels are often used to confirm a diagnosis of a peroxisomal disorder [6]. However, it is essential to note that DNA testing may be more challenging for PBD7B and other peroxisomal disorders.

A clinical genetic test offered by Greenwood Genetic Center Diagnostic Laboratories includes testing genes related to peroxisome biogenesis disorder [4]. Additionally, Blueprint Genetics' Peroxisomal Disorders Panel is ideal for patients with a clinical suspicion of infantile Refsum disease, which is part of the Zellweger syndrome spectrum and may include PBD7B [7].

It's worth noting that biochemical studies performed in blood and urine are used to screen for peroxisome biogenesis disorders, including PBD7B [9]. However, DNA testing is possible but more challenging for these disorders.

References:

[1] Molecular Genetics Tests [4] Clinical Genetic Test offered by Greenwood Genetic Center Diagnostic Laboratories [6] Oct 17, 2023 — Therefore, multigene panels are often used to confirm a diagnosis of a peroxisomal disorder. [7] Nov 13, 2023 — Blueprint Genetics' Peroxisomal Disorders Panel Is ideal for patients with a clinical suspicion of infantile Refsum disease, ... [9] by SJ Steinberg · 2006 · Cited by 610 — Biochemical studies performed in blood and urine are used to screen for the PBD. DNA testing is possible for all of the disorders, but is more challenging for ...

Treatment Options for Peroxisome Biogenesis Disorder 7B (PBD7B)

Peroxisome biogenesis disorder 7B (PBD7B) is a rare genetic disorder that affects the functioning of peroxisomes, which are organelles responsible for breaking down fatty acids and amino acids. While there is currently no cure for PBD7B, various treatment options can help manage its symptoms.

• Cholic Acid Therapy: Cholic acid (CA) therapy has been shown to be effective in reducing toxic bile acid intermediates and improving liver chemistries in patients with PBD-ZSD, which includes PBD7B [8]. CA therapy has also been demonstrated to improve the quality of life for these patients by reducing symptoms such as seizures and developmental delays.
• Adjunctive Treatment: Cholic acid (Cholbam) is approved by the FDA for adjunctive treatment of peroxisomal disorders, including Zellweger spectrum disorders, which includes PBD7B [1]. This treatment can help manage symptoms and improve liver function in patients with PBD7B.
• Symptomatic Treatment: Management of PBD7B is multidisciplinary and symptomatic, focusing on surveillance of multiple systems affected by the disorder [3]. Treatment may include anti-epileptic drugs to control seizures, as well as other medications to manage symptoms such as developmental delays and liver dysfunction.

It's essential for individuals with PBD7B to consult with a healthcare professional for personalized medical advice and treatment. A multidisciplinary team of healthcare providers can work together to develop an effective treatment plan tailored to the individual's specific needs [6].

References:

[1] Nov 30, 2022 — In March 2015, cholic acid (Cholbam) was approved by the FDA for adjunctive treatment of peroxisomal disorders, including Zellweger spectrum ...

[3] by C Argyriou · 2016 · Cited by 92 — There are no curative therapies for PBD. Management is multidisciplinary, symptomatic, and based on surveillance of the multiple systems...

[6] While there is currently no cure for peroxisomal disorders, treatment is symptomatic. It is recommended that individuals diagnosed with peroxisomal disorder...

[8] by GM Enns · 2021 · Cited by 10 — Cholic acid (CA) therapy has demonstrated treatment efficacy in patients with PBD-ZSD, including decreased toxic bile acid intermediates, transaminase levels...

Peroxisome biogenesis disorders (PBDs) are a group of conditions caused by a partial or generalized defect in peroxisome assembly and function [1]. The differential diagnosis for PBDs, specifically the Zellweger spectrum disorder (ZSD), involves identifying other conditions that may present with similar symptoms.

The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, and dysmorphic features [2]. These symptoms can also be seen in other conditions such as:

• Rhizomelic chondrodysplasia punctata (RCDP): a rare genetic disorder characterized by shortening of the long bones of the limbs, particularly the proximal parts [5].
• Neonatal adrenoleukodystrophy (NALD): a severe form of PBD that presents with adrenal insufficiency and leukodystrophy [6].

To differentiate ZSD from other conditions, biochemical studies are performed to detect elevated very-long-chain fatty acids (VLCFA) in the plasma [3]. The primary step in PBD-ZSD diagnosis generally involves the detection of elevated VLCFA in a fasting plasma sample.

Other diagnostic approaches include:

• Genetic testing: to identify mutations in the PEX genes responsible for peroxisome biogenesis disorders [7].
• Imaging studies: such as MRI and CT scans, to assess the extent of neurological involvement and other systemic manifestations [8].

A comprehensive evaluation by a multidisciplinary team of healthcare professionals is essential to establish an accurate diagnosis and develop an effective treatment plan.

References:

[1] C Argyriou · 2016 · Cited by 92 — Introduction. Peroxisome biogenesis disorders (PBD) are a group of conditions caused by a partial or generalized defect in peroxisome assembly and function [1].

[2] The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, and dysmorphic features [2].

[3] by NE Braverman · 2016 · Cited by 261 — The primary step in PBD-ZSD diagnosis generally involves the detection of elevated VLCFA in a fasting plasma sample [19].

[5] by SJ Steinberg · 2006 · Cited by 612 — PBD are divided into two types—Zellweger syndrome spectrum (ZSS) and rhizomelic chondrodysplasia punctata (RCDP).