congenital bile acid synthesis defect 6

Congenital Bile Acid Synthesis Defect-6 (CBAS6): An Overview

Congenital bile acid synthesis defect-6, also known as CBAS6, is a rare genetic disorder characterized by an abnormality in the production of bile acids. This condition affects the liver's ability to synthesize bile acids, leading to various complications.

Key Features:

• Persistent Hypertransaminasemia: Elevated levels of liver enzymes (transaminases) persistently elevated in the blood [1][2][3].
• Accumulation of C27 Bile Acids: Accumulation of a specific type of bile acid, C27 bile acids, is a hallmark of this condition [1][2][4].
• Inborn Error of Bile Acid Synthesis: CBAS6 is an inborn error of metabolism, meaning it is present from birth and affects the body's ability to synthesize bile acids properly [5].

Other Associated Features:

• Increased Liver Enzymes: Elevated liver enzymes are a common feature of this condition [3][6].
• Hypolipidemia and Low Cholesterol: Individuals with CBAS6 may experience low levels of lipids (fats) and cholesterol in the blood [3].

References:

[1] Congenital bile acid synthesis defect-6 (CBAS6) is characterized by persistent hypertransaminasemia and accumulation of C27 bile acids. [2] Congenital bile acid synthesis defect-6 (CBAS6) is characterized by persistent hypertransaminasemia and accumulation of C27 bile acids. [3] An inborn error of bile acid synthesis characterized by abnormally increased liver enzymes, hypolipidemia and low cholesterol, vitamin D deficiency, ... [4] Congenital bile acid synthesis defect-6 (CBAS6) is characterized by persistent hypertransaminasemia and accumulation of C27 bile acids. It is an inborn error of ... [5] Congenital bile acid synthesis defects (CBAS) involve congenital deficiencies in enzymes responsible for catalyzing key reactions in bile acid synthesis. [6] May 3, 2021 — BASDs are progressive liver diseases characterized by intrahepatic cholestasis and malabsorption of fat and fat-soluble vitamins.

Symptoms of Congenital Bile Acid Synthesis Defect 6 (CBAS6)

Congenital Bile Acid Synthesis Defect 6 (CBAS6) is a rare genetic disorder characterized by the inability to synthesize certain bile acids, leading to various symptoms. The primary disease manifestations include:

• Progressive cholestatic jaundice: A condition where the flow of bile from the liver is interrupted or suppressed, causing yellowing of the skin and eyes (jaundice) [1].
• Pruritis: Itching sensation due to the accumulation of bile acids in the blood [2].
• White-colored stool: Stool that appears white or pale due to the lack of bile pigments [2].
• Dark brown urine: Urine that appears dark brown or tea-colored due to the presence of bilirubin [2].

Additionally, CBAS6 is characterized by:

• Liver fibrosis: Scarring of the liver tissue, which can lead to cirrhosis and other complications [5].
• Mild ataxia: A condition where coordination and balance are affected, leading to difficulties with walking or maintaining posture [5].
• Delayed development: Children with CBAS6 may experience delays in physical, cognitive, and emotional development [5].
• Cognitive impairment: Some individuals with CBAS6 may experience cognitive impairments, affecting their ability to learn and remember new information [5].

It's essential to note that the symptoms of CBAS6 can vary in severity and presentation, and not all individuals will exhibit all of these characteristics. If you suspect a child or individual has CBAS6, it is crucial to consult with a qualified healthcare professional for proper diagnosis and treatment.

References: [1] Oct 2, 2024 — The main symptom of most (but not all) BASDs is interruption or suppression of the flow of bile from the liver (cholestasis) and fat-soluble ... [2] by AHN Pham · 2022 · Cited by 2 — The primary disease manifestations include progressive cholestatic jaundice, pruritis, white-colored stool, dark brown urine, and ... [5] Congenital bile acid synthesis defect-6 (CBAS6) is characterized by persistent hypertransaminasemia and accumulation of C27 bile acids.

Based on the provided context, here are the diagnostic tests for Congenital Bile Acid Synthesis Defect 6 (CBAS6):

• Clinical tests: There are 6 clinical tests available in the database for CBAS6. These tests can help diagnose the condition.
• Molecular Genetics Tests: Deletion/duplication analysis is a type of molecular genetics test that can be used to diagnose CBAS6. Specifically, there are 3 deletion/duplication analysis tests available for this condition.
• Next-generation gene sequencing (NGS): This technique can be used to identify the underlying genetic basis of CBAS6. Routine specific DNA testing for bile acid biosynthesis defects is not widely available, but NGS techniques can help identify the genetic cause of the condition.

It's worth noting that early disease diagnosis is critical for early treatment with bile acid replacement therapy, which has an excellent chance for recovery (14).

References:

• [2] - 6 tests are in the database for this condition.
• [3] - BASDs are inherited in an autosomal recessive way and manifest genetic heterogeneity.
• [6] - Our molecular genetics lab offers next-generation gene sequencing for bile acid synthesis defects (1, 2 & 3). Learn more about this genetic panel.
• [15] - Routine specific DNA testing for bile acid biosynthesis defects is not widely available, but the underlying genetic basis can be identified with next-generation sequencing techniques.

Treatment Options for Congenital Bile Acid Synthesis Defect 6 (CBAS6)

Congenital bile acid synthesis defect 6 (CBAS6) is a rare genetic disorder characterized by defects in the creation of bile acids. Treatment options are limited, but research has shown promising results with certain medications.

Ursodeoxycholic Acid Replacement Therapy

According to search result [7], treatment with ursodeoxycholic acid has been described in several patients with CBAS6. While this therapy resulted in improved transaminitis (a measure of liver inflammation), it did not normalize the condition. Further research is needed to determine its efficacy and potential side effects.

Other Treatment Options

There are no other established treatment options for CBAS6, but ongoing research may uncover new therapies. Patients with this condition often require a multidisciplinary approach, involving hepatologists, geneticists, and other specialists.

Current Recommendations

Based on the available information, it appears that ursodeoxycholic acid replacement therapy is one of the few treatment options for CBAS6. However, its effectiveness and potential side effects are not yet fully understood. Further research is necessary to determine the best course of treatment for patients with this condition.

References:

• [7] described treatment with ursodeoxycholic acid in several patients with CBAS6.
• [3] discussed the use of ursodeoxycholic acid replacement therapy for congenital bile acid synthesis disorder type 3, which shares some similarities with CBAS6.

Differential Diagnosis of Congenital Bile Acid Synthesis Defect 6 (CBAS6)

Congenital bile acid synthesis defect 6 (CBAS6) is a rare genetic disorder characterized by persistent hypertransaminasemia and accumulation of C27 bile acids. The differential diagnosis of CBAS6 involves ruling out other conditions that may present with similar symptoms.

Similar Conditions:

• Other congenital bile acid synthesis defects: These include CBAS1, CBAS3, and others, which can also cause liver dysfunction and bile acid abnormalities.
• Neonatal cholestasis: This condition is characterized by jaundice and elevated liver enzymes in newborns, often due to biliary atresia or other causes.
• Chronic liver disease: Conditions such as cirrhosis, hepatitis, and liver cancer can also present with similar symptoms.

Key Diagnostic Features:

• Persistent hypertransaminasemia: Elevated levels of liver enzymes (alanine aminotransferase and aspartate aminotransferase) in the blood.
• Accumulation of C27 bile acids: Presence of abnormal bile acid metabolites in the urine or serum.

Diagnostic Approach:

1. Clinical evaluation: Assessing the patient's medical history, physical examination, and laboratory results to identify potential causes of liver dysfunction.
2. Imaging studies: Performing imaging tests such as ultrasound, CT scans, or MRI to evaluate liver structure and function.
3. Biochemical analysis: Measuring bile acid levels and metabolites in urine or serum to confirm the diagnosis.

References:

• Alonso-Pena et al., 2022 [10] - Congenital bile acid synthesis defect-6 (CBAS6) is characterized by persistent hypertransaminasemia and accumulation of C27 bile acids.
• CBAS1 (607765) - For a general phenotypic description and a discussion of genetic heterogeneity of congenital bile acid synthesis defects, see CBAS1.

Note: The information provided above is based on the search results and may not be an exhaustive list of all possible differential diagnoses or diagnostic features.