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Nicolaides-Baraitser Syndrome

Last updated April 5, 2018

Approved by: Krish Tangella MD, MBA, FCAP

Nicolaides-Baraitser Syndrome (NCBRS) is a very rare condition characterized by severe intellectual disability and various physical features.


What are the other Names for this Condition? (Also known as/Synonyms)

  • NCBRS (Nicolaides-Baraitser Syndrome)
  • Sparse Hair and Mental Retardation

What is Nicolaides-Baraitser Syndrome? (Definition/Background Information)

  • Nicolaides-Baraitser Syndrome (NCBRS) is a very rare condition characterized by severe intellectual disability and various physical features
  • Signs and symptoms may include seizures, short stature, sparse hair, distinctive facial characteristics, short fingers and toes (brachydactyly), and prominent joints in the fingers and toes (interphalangeal joints)
  • Features of the condition can worsen over time. NCBRS is caused by changes (mutations) in the SMARCA2 gene and is inherited in an autosomal dominant manner
  • All cases reported to date have been sporadic, occurring in people with no family history of NCBRS

(Source: Nicolaides-Baraitser Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Nicolaides-Baraitser Syndrome? (Age and Sex Distribution)

  • Nicolaides-Baraitser Syndrome is an extremely rare congenital disorder. The presentation of symptoms may occur at birth
  • Both males and females may be affected
  • Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Nicolaides-Baraitser Syndrome? (Predisposing Factors)

  • A positive family history may be an important risk factor, since Nicolaides-Baraitser Syndrome can be inherited
  • Currently, no other risk factors have been clearly identified for NCBRS

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Nicolaides-Baraitser Syndrome? (Etiology)

Nicolaides-Baraitser Syndrome (NCBRS) is caused by mutations in the SMARCA2 gene, which is located on the small arm of chromosome 9.

  • All mutations that have been identified in affected people have been either missense mutations or in-frame deletions
  • There may be some correlations between specific types of mutations and some of the features that result (called genotype-phenotype correlations), but more studies are needed to draw definitive conclusions
  • Nicolaides-Baraitser syndrome (NCBRS) is inherited in an autosomal dominant manner. This means that having a change (mutation) in only one of the two copies of the responsible gene in each cell is enough to cause features of the condition
  • All known cases of NCBRS have been sporadic. This means it is thought that the mutation occurred for the first time in each affected person (called a de novo mutation)

There have not been reports of NCBRS being inherited from a parent, or recurring in any family (with the exception of one pair of identical twins).

(Source: Nicolaides-Baraitser Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Nicolaides-Baraitser Syndrome?

The signs and symptoms of Nicolaides-Baraitser Syndrome may include:

  • Absent speech
  • Aggressive behavior
  • Anteverted nares
  • Brachydactyly
  • Broad philtrum
  • Cryptorchidism
  • Everted lower lip vermilion
  • Failure to thrive
  • Intellectual disability, severe
  • Intrauterine growth retardation
  • Long philtrum
  • Low anterior hairline
  • Microcephaly
  • Poor speech
  • Prominent interphalangeal joints
  • Sandal gap
  • Seizures
  • Short metacarpal
  • Short metatarsal
  • Short phalanx of finger
  • Sparse scalp hair
  • Thick lower lip vermilion
  • Triangular face
  • Wide mouth
  • Wide nasal base

Rarely present symptoms in 1-4% of the cases:

  • Downslanted palpebral fissures
  • Eczema
  • Narrow nasal bridge
  • Scoliosis
  • Unilateral narrow palpebral fissure
  • Widely spaced teeth

(Source: Nicolaides-Baraitser Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Nicolaides-Baraitser Syndrome Diagnosed?

Nicolaides-Baraitser Syndrome is diagnosed on the basis of the following information:

  • Complete physical examination
  • Thorough medical history evaluation
  • Assessment of signs and symptoms
  • Laboratory tests
  • Imaging studies
  • Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Nicolaides-Baraitser Syndrome?

The complications of Nicolaides-Baraitser Syndrome may include:

  • Physical deformities
  • Bone disorders
  • Intellectual impairment
  • Reduced quality of life

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Nicolaides-Baraitser Syndrome Treated?

There is no cure for Nicolaides-Baraitser Syndrome, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complications that develop.

How can Nicolaides-Baraitser Syndrome be Prevented?

Currently, Nicolaides-Baraitser Syndrome may not be preventable, since it is a genetic disorder. If there is a family history of the condition:

  • Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
  • Genetic counseling will help assess risks, before planning for a child
  • Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Nicolaides-Baraitser Syndrome? (Outcomes/Resolutions)

There is limited information about the life expectancy of people with Nicolaides-Baraitser syndrome (NCBRS) due to the rarity of the condition and the small number of reported cases in the literature. NCBRS was not recognized as a distinct condition until the 1990s, so there is limited information about older adults with NCBRS.

  • As of 2009, the first person reported with NCBRS was still living at age 32. Another person first reported in 1996 died at the age of 25 due to rupture of esophagus varices (the cause of which was not known)
  • Also as of 2009, two French people, reported at ages 6 and 22 in 2003, were in excellent health without new physical problems and without progression of existing signs and symptoms
  • While some features of NCBRS are always present, there is variability, and the severity of features may range from mild to severe. Therefore, the long-term outlook (prognosis) may vary among affected people

Certain features of NCBRS can change or be progressive over time:

  • Scalp hair is usually sparse at birth and usually becomes increasingly sparse with age, particularly in the second decade of life. However in some, the sparseness improves with time
  • Facial characteristics typically become more pronounced with increasing age. In some affected adults, the lower third of the face becomes markedly broad
  • As people with NCBRS age, the amount of subcutaneous fat tissue tends to decrease, making the skin below the eyes sagging and wrinkled, especially at the cheeks when smiling. However, some affected people retain full cheeks
  • The distal phalanges widen with age, becoming oval shaped and broad. Increasing space between the first and second toes can also occur over time. At first, finger mobility is normal (maybe even hypermobile). Later on mobility often decreases, and some older people dislike passive movements of their fingers
  • Osteoporosis is not uncommon and affected people may develop fractures in puberty or thereafter
  • Although psychomotor regression is not typical, the high incidence of seizures that progressively worsen has been associated with loss of speech

(Source: Nicolaides-Baraitser Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Additional and Relevant Useful Information for Nicolaides-Baraitser Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/

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Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: April 5, 2018
Last updated: April 5, 2018