Congenital bile acid synthesis defect type 3

What it is

From: Orphanet

Congenital bile acid synthesis defect type 3 (BAS defect type 3) is a severe anomaly of bile acid synthesis characterized by severe neonatal cholestatic liver disease.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormality of vitamin metabolism · Frequent (79-30%)

An anomaly in the metabolism of a vitamin.

Bile duct proliferation · Frequent (79-30%)

Proliferative changes of the bile ducts.

Cholestasis · Frequent (79-30%)

Impairment of bile flow due to obstruction in bile ducts.

Cirrhosis · Frequent (79-30%)

A chronic disorder of the liver in which liver tissue becomes scarred and is partially replaced by regenerative nodules and fibrotic tissue resulting in loss of liver function.

Elevated circulating alanine aminotransferase concentration · Frequent (79-30%)

An abnormally high concentration in the circulation of alanine aminotransferase (ALT).

Elevated circulating alkaline phosphatase concentration · Frequent (79-30%)

Abnormally increased serum levels of alkaline phosphatase activity.

Elevated circulating aspartate aminotransferase concentration · Frequent (79-30%)

The concentration of aspartate aminotransferase (AST) in the blood circulation is above the upper limit of normal.

Fat malabsorption · Frequent (79-30%)

Abnormality of the absorption of fat from the gastrointestinal tract.

Hepatosplenomegaly · Frequent (79-30%)

Simultaneous enlargement of the liver and spleen.

Hyperbilirubinemia · Frequent (79-30%)

An increased amount of bilirubin in the blood.

Jaundice · Frequent (79-30%)

Yellow pigmentation of the skin due to bilirubin, which in turn is the result of increased bilirubin concentration in the bloodstream.

Hepatic failure · Frequent (79-30%)

When it may begin

From: Orphanet

Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 2.0; Worldwide. This is a published case count, not prevalence. Point prevalence: <1 / 1 000 000; Worldwide; Class only.

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing Congenital bile acid synthesis defect type 3 is Hepatology, with a hepatologist / gastroenterologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• What is known about the cause and extent of liver involvement?
• Which medicines, supplements or exposures should be reviewed?
• What follow-up is appropriate for the specific diagnosis and stage?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Congenital bile acid synthesis defect type 3. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.