Bjornstad syndrome
Findings
No curated finding names Bjornstad syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Bjrnstad syndrome is characterized by congenital sensorineural hearing loss and pili torti. Less than fifty cases have been reported so far. The hearing loss usually becomes evident very early in life, often in the first year. Pili torti, a condition in which the hair shaft is flattened and twisted, makes the hair very brittle and patients develop hair loss in the first two years of life. Bjrnstad syndrome is transmitted as an autosomal recessive condition. It is caused by mutations in the BCS1L gene. Mutations in this gene also cause GRACILE syndrome.
Definition from the Mondo Disease Ontology (MONDO:0009872), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset
HPO, annotations 2026-09-02
Features
13 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- AlopeciaHPOHP:0001596
- 5 of 5 reported patients
- Very frequent (80% to 99% of cases)
- AnhidrosisHPOHP:0000970
- 5 of 5 reported patients
- Pili tortiHPOHP:0003777
- 5 of 5 reported patients
- Very frequent (80% to 99% of cases)
- Sensorineural hearing impairmentHPOHP:0000407
- 5 of 5 reported patients
- Very frequent (80% to 99% of cases)
- Aplasia/Hypoplasia of the eyebrowHPOHP:0100840
- Very frequent (80% to 99% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- BCS1LHGNC:1020
- Definitive · ClinGen · Autosomal recessive · 2018
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Moderate · Ambry Genetics · Autosomal recessive · 2018
- Supportive · Orphanet · Autosomal recessive · 2021
- Limited · G2P · Autosomal dominant · 2025
Where it sits
Other names
2 names
Resolves to: Bjornstad syndrome
- Also called
- Björnstad Syndromedeafness-pili torti-hypogonadism syndrome