Most Common Features

Almost all children with WAC syndrome who have been identified to-date have:

• Learning disabilities

• Developmental delay

• Low muscle tone (hypotonia) particularly affecting the mouth and throat area, resulting in poor articulation (dysarthria) and swallowing difficulties

• Behavioural problems, including autism spectrum disorder, ADHD (attention deficit hyperactivity disorder), sleep disorders and anxiety

• A characteristic facial appearance, typified by a square-shaped head; 4 deep-set, long eyes; a wide mouth; a broad chin; and minor ear anomalies. These features are not observed in all individuals and are not specific to WAC syndrome. 

Physical Development

Almost all children experience a delay in meeting their motor development milestones, such as rolling, crawling and walking. The age at which children achieve independent walking ranges from 12 to 36 months.

Learning

The majority of children with WAC syndrome have a mild intellectual disability (ID) (a moderate to severe ID was observed in fewer than one in five children). Reported IQ values range from 44 to 98. Extensive psychocognitive evaluation of some of the children revealed relative difficulties in non-verbal skills and in sustaining attention and maintaining focus. Basic language skills and verbal memory skills are areas of relative strength.

Behavior

A variety of behavioral problems are known to be part of WAC syndrome including ADHD, autism, anxiety, sleep disturbances and aggression.

SPEECH

A delay in language development is observed in almost all children with WAC syndrome. The age at which children speak their first words ranges from 14 months to five years. Only a small minority of children remain non-verbal. Due to low muscle tone around the mouth and throat, some children have problems with articulation (dysarthria).

Fine motor SKills

Development of hand use and hand-eye coordination are impaired in children with WAC syndrome. Children usually benefit from physiotherapy and occupational therapy.

Growth

Growth Babies with WAC syndrome are usually born at a normal birth weight and continue to grow at the expected rate. Some children have problems maintaining their weight within a normal range, while some instances of children who are overweight have been reported.

Low muscle tone

Low muscle tone (hypotonia) is obvious in around half to three quarters of children and may persist throughout childhood. The condition is particularly severe around the mouth and throat area, resulting in poor pronunciation and swallowing difficulties.

Feeding difficulties

Feeding difficulties in the neonatal period have been reported, including gastroesophageal reflux disease (GERD). For some babies who are more severely affected, temporary feeding by nasogastric tube may be necessary.

CONSTIPATION

Constipation has been observed in several children with WAC syndrome.

SEIZURES

Several children are known to have epilepsy. An EEG should be undertaken if seizures are suspected. Cases of 7 tonic-clonic seizures, absence episodes and febrile convulsions have been reported.

EYES + EYESIGHT ISSUES

A wide range of eye and eyesight problems have been reported. These include but are not limited to: unexplained reduced vision or cortical visual impairment (an inability of the brain to interpret what the eyes can see), long -sightedness and strabismus (a squint).

RESPIRATORY ISSUES

Recurrent respiratory infections have been reported in almost half of children in the medical literature, most frequently in childhood. Cases of asthma and an abnormal breathing pattern have also been observed.

NEUROIMAGING ANOMALIES

Some children have non-specific anomalies of the brain, of which an enlargement of the fluid-filled ventricles in the brain is the most frequently reported. This may interfere with the body's ability to drain cerebrospinal fluid from the brain resulting in hydrocephalus - a build-up of fluid within the brain. Ventriculomegaly and prominence/enlargement of subarachnoid spaces have each been reported on a few occasions. Other findings include asymmetry of the hemispheres of the brain. 

HIRSUTISM

In some children, excessive hairiness on parts of the body where normally hair is absent or minimal has been observed.

OTHER BIRTH ANOMALIES

A wide range of congenital anomalies have been described, but none of them have been found recurrently in children with WAC syndrome. Reports include: kidney anomalies; occlusion of the tear duct; an abnormality of the windpipe (trachea); hip dysplasia; hearing loss; anomalies of the feet and hands; hypogammaglobulinemia associated with recurrent infections; leukopenia and thrombocytopenia; and diaphragmatic hernia (the sheet of muscle between the abdomen and the chest is not complete, allowing organs from the abdomen to be displaced into the chest). Children with 10p12p11 deletions that include WAC as well as neighbouring genes tend to have more medical concerns than children with changes confined to the WAC gene alone. Heart abnormalities in particular seem to be more frequently observed in children with 10p12p11 deletions.