What is NCBRS ?
Nicolaides-Baraitser Syndrome (NCBRS) is a rare genetic condition that is present at birth, is usually recognized during childhood, and can affect anyone. NCBRS does not discriminate. It is known to occur in both males and females, and in every culture. Currently there are less than 100 confirmed cases worldwide.
Cause and Diagnosis of NCBRS
NCBRS is caused by a change in a gene called SMARCA2 that has started in a child and is not present in either parent.
The diagnosis of NCBRS can be made in two ways.
- A clinical diagnosis: this diagnosis is made by a geneticist based on the characteristics. One may subsequently try to confirm the clinical diagnosis by genetic blood test, using a sample of the child's blood. One analyzes specifically the SMARCA2 gene for changes. Until now, in every child that was reliably diagnosed clinically as having NCBRS, a change in the gene SMARCA2 has been found.
- A molecular diagnosis: a change in the SMARCA2 gene is identified through a blood test analyzing many genes simultaneously in a child who has developmental delay. Thereafter, one goes back to the child and often only then it is recognized that at least some (and often many) of the characteristicsof NCBRS are present.
NOTE: It is extremely rare that another family member has NCBRS. For parents of a child with NCBRS, the probability of having a second affected child is extremely low. It is possible however, if in a family NCBRS is detected in a child and a change in the gene has been found, to check in a subsequent pregnancy (through prenatal diagnosis) whether the fetus has the same change in the SMARCA2 gene as the child with NCBRS. It should be noted that if the individual with NCBRS plans to become a parent himself or herself, there is a 50 percent chance that his or her child will have NCBRS.
Typical Features of NCBRS include
Face - most individuals with NCBRS are described as having similar features. The face is usually triangular in shape, dense eyelashes, prominent nose with thick nostrils, thin upper lip, full lower lip and wide mouth. With increasing age, the subcutaneous fat in the cheeks decreases, making the skin sag and wrinkle. Typically, the facial characteristics become much more pronounced with age.
Teeth - are widely spaced. Delayed eruption of the baby and adult teeth is not uncommon.
Hair - sparse scalp hair is a key sign of NCBRS. It has been reported in nearly all diagnosed cases. The growth and texture is normal. It has been noted in some cases that overtime the sparseness of the hair increases, while in others it decreases with time. Pubic hair develops normally, and in adult males, facial hair is limited.
Skin - Eczema and skin sensitivity has occurred in a third of diagnosed cases.
Hands - as the child ages, the finger tips become broad and the joints become more prominent.
Hernias - groin and umbilical hernias are more common in individuals with NCBRS than the general population.
Undescended testes - is present in about 60% of boys, often requiring surgery.
Scoliosis - has occured in less than a third of children. It ranges from mild to severe.
Epilepsy - is a common sympton of NCBRS. With many parents reporting that the seizures started in the first two years of life.. Many of the children will have very few seizures, but in some cases the seizures will increase in frequency. Indeed many of the children take some form of anti-seizure medication daily.
Autistic-like behaviours - some children will display austistic behaviours such as obsessions, short attention span, sensitivity to loud noises, repetitive behaviours and routines. It has been stated that in many cases the children have a lack of awareness to certain dangers.
Children with NCBRS have a delightful personality. They are typically very happy and always seem to have a beautiful smile on their face. Often they are over friendly and do not appear to be afraid of strangers. As they get older in has been noted that during and after puberty, they develop more temper tantrums, become more stubborn and occasionally show more aggression.
Development and Behaviour
Developmental delay - most individuals with NCBRS will have an intellectual disability ranging from mild to severe. Young children will typically struggle to reach certain expected milestones. Low muscle tone is reported in one third of children with NCBRS, but major motor milestones such as sitting (mean 9 months) and walking independently (mean 21 months) are usually not very delayed. Language delays are often present varying from limited speech to completely non-verbal. It has to be noted, although not typical, there are some children who develop full speech.
Feeding problems - many infants and young children will have some kind of feeding problem. This can be related to severe gag reflex, gastroesophageal reflux, poor suck/swallow, low muscle tone and sensitivity to textures. Feeding diffiulties usually resolve as the child gets older.
A third of babies with NCBRS are smaller than average at birth.
Microcephaly is present in more than half of the children..
Short stature is very common, studies have shown that nearly all children are below the 50th percentile.
Slow weight gain is an issue, especially during the early years. In some cases the children are diagnosed as failure to thrive.
Naming the Syndrome
The designation derives from the name of the two doctors who observed the first person identified with this syndrome. They were pediatric neurologist Paola Nicolaides and clinical geneticist Michael Baraitser, from Great Ormond Street Hospital, London. Back in 1993, they wrote the story of June in a scientific journal, raising the hypothesis that her unusual combination of features could constitute a non-previously described syndrome.