Bjornstad syndrome is a rare autosomal recessive genetic disorder characterized by brittle and fragile short hair (known as pili torti) and hearing loss that appear in the first several years of life. The disease stems from mutations in the BCS1L proteins that are responsible for mitochondrial function. Additional findings are hypogonadism and mental retardation. The diagnosis can be made based on clinical findings, a positive family history, and genetic studies that confirm the specific mutation.
Presentation
Initially described 50 years ago, Bjornstad syndrome (BS) is a rare genetic disorder that arises due to mutations in BCS1L proteins that play an essential role in mitochondrial function [1] [2] [3] [4]. The location of genes that code for these proteins was subsequently identified on chromosome 2 and an autosomal recessive pattern of inheritance was established [1] [2] [3]. Very few cases of BS have been described in the literature. The clinical presentation is centered around two components - pili torti and hearing loss [3] [5] [6]. Pili torti (denoting the twisting of hair around their axis) is a term used to illustrate the appearance of short and brittle hair (without any pigment) that occurs as a result of the previously mentioned mutations, consequently leading to hair loss in the first few years of life [1] [5] [6]. For some reason, the hair on the head is principally affected, whereas the other parts of the body (including the face) are spared. Conversely, hearing loss is congenital in nature and develops by three years in the majority of cases [1] [5]. The severity of hearing impairment may be mild, moderate, or severe enough to lead to deafness [1] [3]. Isolated studies have reported mental retardation and hypogonadism as additional signs of BS [5].
Ears
- Hearing Impairment
Björn·stad syn·drome (byōrn'stahd), [MIM*262000] pili torti associated with sensorineural hearing loss, the severity of distortion and brittleness of the hair correlated with the degree of hearing impairment; autosomal dominant inheritance. [medical-dictionary.thefreedictionary.com]
Conversely, hearing loss is congenital in nature and develops by three years in the majority of cases. The severity of hearing impairment may be mild, moderate, or severe enough to lead to deafness. [symptoma.com]
[…] correlated with the degree of hearing impairment; autosomal dominant inheritance. [checkorphan.org]
- Progressive Hearing Loss
They each experienced a varying degree of progressive hearing loss as well as hair loss on the scalp. [en.wikipedia.org]
- Normal Hearing
Introduction The Björnstad syndrome is an autosomal recessive condition characterized by sensorineural hearing loss and pili torti.1,2 The hearing loss in the Björnstad syndrome is congenital and of variable severity. [nejm.org]
Introduction The Björnstad syndrome is an autosomal recessive condition characterized by sensorineural hearing loss and pili torti. 1,2 The hearing loss in the Björnstad syndrome is congenital and of variable severity. [doi.org]
Skin
- Alopecia
Ketogenic diet for treating alopecia in BCS1l-related mitochondrial disease (Bjornstad syndrome). [news-medical.net]
The treatment of patchy hair loss (alopecia) may include the use of wigs and/or other hair replacement therapies. [rarediseases.org]
- Anhidrosis
Other symptoms may include anhidrosis (lack of sweating), coarse or dry hair, and pili torti of variable intensity. [news-medical.net]
[…] symptoms typically appear before the age of 2 and are present in 80-99% of individuals with Björnstad syndrome.[4] Approximately 5-29% of individuals also experience intellectual disabilities and hypogonadism.[4] Cases showing lack of hair pigmentation and anhidrosis [en.wikipedia.org]
- Sparse Hair
In some cases, the hair anomalies are accompanied by partial or almost total alopecia, while other patients have no signs of sparse hair. [accesspediatrics.mhmedical.com]
Clinical examination showed dry, lustreless, fragile, and brittle hair of scalp and sparse hairs involving eyebrows [Figure 1]. [ijtrichology.com]
seizures Monilethrix - AD, human hair keratin hHb1 and hHb6 - beaded hair with elliptical nodes along hair shaft, KP Trichorhinophalangeal Syndrome - AR/AD, TRPS 1 gene - sparse hair, pear-shaped nose, cone-shaped epiphyses Uncombable hair syndrome [studyblue.com]
- Dry, Brittle Hair
Björnstad Syndrome Björnstad syndrome is characterized by hearing loss (sensorineural deafness) and dry, brittle hair (pili torti). Children with Björnstad syndrome usually have mild to severe hearing loss within the first two years of life. [myriad.com]
Workup
Given the rare occurrence of Bjornstad syndrome in clinical practice (approximately 20 cases have been described by the end of the 20th century) [2], the diagnosis may be difficult to attain. For this reason, the physician must obtain a detailed patient history and perform a meticulous physical examination that will provide the opportunity to identify the hallmarks of BS. The onset of deafness and hair loss must be assessed with the parents of the affected child, as most cases are described in infancy or early childhood. In addition, a complete family history that covers the presence of similar findings in siblings or parents might be of great benefit for raising clinical suspicion toward a familial disorder. Auditory testing should be conducted in order to determine the extent of hearing loss, whereas microscopic examination of the hair will reveal typical twists of the hair shaft that must point to BS [4] [7]. Transmission electron microscopy (TEM) has been used (where possible) as a method to confirm pili torti [4] [6]. To confirm the diagnosis, however, genetic testing to detect BCS1L mutations is a mandatory procedure.
Treatment
Treatment The treatment may require the coordinated efforts of different medical specialists such as pediatricians, audiologist and dermatologist who may determine an effective treatment plan for the affected individual. [mybiosource.com]
Patients with Bjornstad syndrome do not have a specific treatment. Treatment is symptomatic and supportive, focusing on the specific symptoms that each kid is experiencing. [news-medical.net]
Most treatments for GRACILE syndrome are aimed at making infants comfortable until they pass away. There is no known treatment for GRACILE syndrome that extends lifespan. [myriad.com]
The treatment of patchy hair loss (alopecia) may include the use of wigs and/or other hair replacement therapies. [rarediseases.org]
Prognosis
Prognosis - Bjornstad syndrome Not supplied. Treatment - Bjornstad syndrome Not supplied. Resources - Bjornstad syndrome [checkorphan.org]
[…] torti with/without alopecia of scalp; eyebrows, eyelashes unaffected Ear Nose Throat Bilateral sensorineural deafness D/Dx Crandall syndrome (pili torti, deafness, hypogonadism) Menkes' syndrome Lab Auditory testing Management Referral to audiologist Prognosis [cram.com]
What Is the Prognosis for Individuals with a BCS1L-Related Disorder? Even with the best possible treatment, most babies with GRACILE syndrome will die within four months of birth. [myriad.com]
Although this syndrome was described 40 years ago, little has been reported about its cardiovascular manifestations and its prognosis. [scielo.br]
Etiology
Etiology Björnstad syndrome is caused by mutations in the BCS1L gene. Mutations in this gene also cause GRACILE syndrome (see this term). Genetic counseling Björnstad syndrome is transmitted as an autosomal recessive condition. [rareguru.com]
However, the variable mode ofinheritance of this syndrome, and its unknown etiology,call for further investigation.REFERENCES1. Bjornstad R. [documents.tips]
Etiology Bjornstad syndrome is caused by mutations in the BCS1L gene. Mutations in this gene also cause GRACILE syndrome (see this term). Genetic counseling Bjornstad syndrome is transmitted as an autosomal recessive condition. [malacards.org]
We also conclude that Williams syndrome is not an uncommon cause of mental retardation, with a prevalence of approximately 6% of patients with genetic etiology. (J Child Neurol 2002;17:269-271). [journals.sagepub.com]
Epidemiology
Epidemiology Less than fifty cases have been reported so far. Clinical description The hearing loss usually becomes evident very early in life, often in the first year. [rareguru.com]
Summary Epidemiology Less than fifty cases have been reported so far. Clinical description The hearing loss usually becomes evident very early in life, often in the first year. [orpha.net]
Genetic epidemiological studies of early-onset deafness in the U.S. school-age population. Am J Med Genet. 1993 Jun 15;46(5):486–491. [PubMed] [Google Scholar] Morton NE. Genetic epidemiology of hearing impairment. Ann N Y Acad Sci. 1991;630:16–31. [ncbi.nlm.nih.gov]
Epidemiology To date, less than 50 cases of Bjornstad syndrome have been reported worldwide. The syndrome affects both genders equally. [news-medical.net]
Google Scholar | Medline Åkefeldt A., Gillberg C., Larsson C. : Prader Willi syndrome in a Swedish rural county: Epidemiological aspects. Dev Med Child Neurol 1991;33:715-721. [journals.sagepub.com]
Pathophysiology
This book will help you understand the basic pathophysiology, clinical presentation, and the most effective treatment options for patients with hair-growth disorders. [books.google.it]
"Brugada" syndrome: clinical data and suggested pathophysiological mechanism. Circulation. 1999 Feb 9. 99(5):666-73. [Medline]. Meregalli PG, Wilde AA, Tan HL. [emedicine.medscape.com]
A wide range of changes associated with pili torti suggest specific pathophysiological mechanisms, which have irregular hair shafts as their common denominator. Morphological studies of its axis showed no abnormalities in the hair cortex keratin. [scielo.br]
Prevention
The mutation prevents the normal assembly of BCS1L monomers into a hexameric unit that guides the Rieske iron–sulfur protein into complex III of the mitochondrial respiratory chain (see diagram). [hms.harvard.edu]
NIOSH leads a national initiative called Prevention through Design (PtD). PtD’s purpose is to promote this concept and highlight its importance in all business decisions. [malacards.org]
Biochemical studies provided evidence to support this model: complex III deficiency mutations prevented ATP-dependent assembly of BCS1L-associated complexes. [ncbi.nlm.nih.gov]
Prevention - Bjornstad syndrome Not supplied. Diagnosis - Bjornstad syndrome Not supplied. Prognosis - Bjornstad syndrome Not supplied. Treatment - Bjornstad syndrome Not supplied. Resources - Bjornstad syndrome [checkorphan.org]
European Journal of Cardiovascular Prevention and Rehabilitation 2010, 17:1-17. [medicina.ucm.es]
References
- Hinson JT, Fantin VR, Schönberger J, et al. Missense mutations in the BCS1L gene as a cause of the Björnstad syndrome. N Engl J Med. 2007;356(8):809-819.
- Lubianca Neto JF, Lu L, Eavey RD, et al. The Bjornstad syndrome (sensorineural hearing loss and pili torti) disease gene maps to chromosome 2q34-36. Am J Hum Genet 1998;62:1107-1112.
- Siddiqi S, Siddiq S, Mansoor A, et al. Novel mutation in AAA domain of BCS1L causing Bjornstad syndrome. J Hum Genet. 2013;58(12):819-821.
- Zhang J, Duo L, Lin Z, et al. Exome sequencing reveals novel BCS1L mutations in siblings with hearing loss and hypotrichosis. Gene. 2015;566(1):84-88.
- Selvaag E. Pili torti and sensorineural hearing loss: a follow-up of Bjornstad's original patients and a review of the literature. Eur J Dermatol. 2000;10:91-97.
- Marubashi Y, Yanagishita T, Muto J, et al. Morphological analyses in fragility of pili torti with Björnstad syndrome. J Dermatol. 2017;44(4):455-458.
- Scott MJ Jr, Bronson DM, Esterly NB. Björnstad syndrome and pili torti. Pediatr Dermatol. 1983;1(1):45-50.