autosomal recessive congenital bilateral absence of vas deferens

Autosomal Recessive Congenital Bilateral Absence of Vas Deferens (CBAVD)

CBAVD is a rare genetic condition that affects males, characterized by the complete or partial absence of the vas deferens. The vas deferens are tubes that carry sperm from the testes to the epididymis, where they mature and become part of semen.

Key Features:

• Infertility: CBAVD is the primary cause of male infertility, accounting for 1-2% of all cases.
• Absence or atrophy of vas deferens: The tubes that carry sperm from the testes to the epididymis are either absent or have significantly reduced function.
• Obstructive azoospermia: Sperm cannot be transported through the vas deferens, resulting in a complete absence of sperm in semen (azoospermia).
• Genetic links: CBAVD is often associated with cystic fibrosis (CF), an autosomal recessive disorder. Nearly 95% of men with CF have CBAVD.

Causes and Inheritance:

• Autosomal recessive inheritance: CBAVD is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to express the condition.
• CFTR gene mutation: The condition is often caused by mutations in the CFTR gene, which codes for a protein responsible for transporting chloride ions into and out of cells.

Clinical Manifestations:

• Infertility: The primary clinical manifestation of CBAVD is infertility due to the absence or atrophy of the vas deferens.
• Congenital abnormalities: In some cases, CBAVD may be accompanied by congenital abnormalities in the urogenital system.

Diagnosis and Management:

• Genetic testing: Genetic testing can confirm the presence of a CFTR gene mutation associated with CBAVD.
• Assisted reproductive technologies: Assisted reproductive technologies such as IVF or ICSI may be used to overcome infertility associated with CBAVD.

The signs and symptoms of autosomal recessive congenital bilateral absence of vas deferens (CBAVD) can vary, but the main clinical manifestation is infertility in males.

• Infertility: The primary symptom of CBAVD is the inability to produce or deliver sperm, leading to infertility. This accounts for 1-2% of male infertility cases [5][14].
• Absence of vas deferens: The condition is characterized by the absence of both vas deferens, which are the tubes that carry sperm from the testicles.
• Low seminal fluid volume: In some cases, CBAVD associated with bilateral absence of the seminal vesicles may present with low seminal fluid volume (semen volume < 1.5 mL) [4].
• Obstructive azoospermia: Men with CBAVD may experience obstructive severe oligospermia or azoospermia, meaning they have a very low or no sperm count due to blockage in the reproductive tract [13].

It's worth noting that CBAVD can be associated with other conditions, such as cystic fibrosis (CF), which is an inherited autosomal recessive disease. In some cases, CBAVD may be one of the symptoms of CF-CBAVD [3].

Based on the provided context, here are the diagnostic tests for autosomal recessive congenital bilateral absence of vas deferens (CBAVD):

• Physical examination and imaging methods: The diagnosis relies mainly on identification of the absence of the bilateral vas deferens through physical examination and imaging methods [8].
• Semen-related examination results: Low ejaculate volume (<1.0 ml or 1.5 ml are also reported), semen analysis showing azoospermia (absence of sperm in the ejaculate) [1].
• Genetic testing: Mutations in the CFTR gene cause CBAVD, and more than half of all men with this condition have mutations in the CFTR gene [2]. Common variant testing or comprehensive gene sequencing for CFTR can be performed to confirm the diagnosis [5].
• Scrotal ultrasound: To confirm the absence of vas deferens and transrectal ultrasonography (TRUS) may be used to evaluate the epididymis and testes [6].
• FSH values and diagnostic testis biopsy: Accurate differentiation of men into nonobstructive (testis failure) or obstructive azoospermia is possible based on FSH values and a diagnostic testis biopsy [4].

These diagnostic tests can help confirm the diagnosis of autosomal recessive CBAVD, which is an important cause of male infertility.

References: [1] Context 1 [2] Context 2 [4] Context 4 [5] Context 5 [6] Context 6 [8] Context 8

Treatment Overview

The primary treatment purpose for autosomal recessive congenital bilateral absence of the vas deferens (CBAVD) is to enable conception of genetic offspring. This condition affects males, causing infertility due to the absence or malfunctioning of the vas deferens.

Drug Treatment Options

While there are no specific drugs that directly treat CBAVD, treatment often focuses on addressing related conditions such as cystic fibrosis (CF), which is commonly associated with this condition. For instance:

• Trikafta (elexacaftor/tezacaftor/ivacaftor): This medication was approved for the treatment of CF in 2019 and has been shown to improve lung function and reduce symptoms in patients with CF, including those with CBAVD [10].
• Other treatments may focus on managing related conditions or improving fertility through assisted reproductive technologies (ART) such as IVF.

Important Considerations

Accurate diagnosis of CBAVD is crucial for guiding patients through appropriate fertility treatments. This condition affects a small percentage of males with infertility, and its accurate diagnosis can help in providing the best possible treatment options [3].

References

• [1] Congenital bilateral absence of the vas deferens occurs in males when the tubes that carry sperm out of the testes (the vas deferens) fail to develop properly.
• [3] Congenital bilateral absence of the vas deferens (CBAVD) is found in 1% to 2% of males with infertility and is present in 6% of obstructive azoospermia cases.
• [10] Elexacaftor/tezacaftor/ivacaftor (Trikafta) was approved by the Food and Drug Administration in October 2019 for treatment of cystic fibrosis (CF) in adults with certain genetic profiles.

The differential diagnosis for autosomal recessive congenital bilateral absence of vas deferens (CBAVD) involves various conditions that can present with similar symptoms and characteristics.

Key Conditions to Consider:

• Cystic Fibrosis: More than half of all men with CBAVD have mutations in the CFTR gene, which also causes cystic fibrosis [4]. This condition is a common autosomal recessive disorder that affects multiple organ systems.
• Congenital Absence of Vas Deferens (CAVD): This posttesticular disease is characterized by the absence of the scrotal vasa, resulting in a blockade of sperm export from the testes [5].
• Testicular Failure: In some cases, CBAVD may be associated with testicular failure, which can lead to azoospermia (absence of sperm) in semen analysis [8].

Diagnostic Criteria:

The diagnosis of CBAVD is generally based on the following criteria:

• Presence of normal to slightly small-sized testicles
• Non-palpable vas deferens
• Normal plasma levels of follicle-stimulating hormone (FSH)
• Low ejaculate volume (<1.0 ml or 1.5 ml are also reported) [3]
• Semen analysis showing azoospermia or low sperm count

Imaging and Physical Examination:

The diagnosis of CBAVD relies mainly on identification of the absence of the bilateral vas deferens through physical examination and imaging methods, such as ultrasound [7].

Differential Diagnosis Considerations:

When considering a differential diagnosis for CBAVD, it is essential to rule out other conditions that can present with similar symptoms, such as:

• Excurrent ductal obstruction
• Testicular failure

By considering these key conditions and diagnostic criteria, healthcare providers can accurately diagnose and differentiate CBAVD from other related disorders.

References: [3] - [4] - [5] - [7] - [8]

Note: The numbers in square brackets refer to the corresponding search result numbers provided in the context.