Saethre-Chotzen syndrome

Saethre-Chotzen (SCS) is a genetic congenital syndrome characterized by the premature fusion/closure of certain skull bones (craniosynostosis) during development. This early fusion affects the shape of the head and facial bones. Symptom severity varies widely among individuals, even in the same family. Often there is asymmetry of the skull and facial bones due to the skull bones (sutures) fusing at different times. Other features include webbing or fusion of certain fingers or toes. Most all with this syndrome have typical intelligence but there have been exceptions. As with other craniosynostosis conditions, there can be overlap with features; therefore, genetic testing is recommended to determine the correct syndrome. Early management of the craniosynostosis is important to ensure proper growth.

Characteristics of SCS may include:

Premature closure of the cranial sutures (craniosynostosis)
Misshapen head/facial malformations/facial asymmetry
Cranial suture closure delay past what is typical for some babies/toddlers
Wide skull shape
High forehead/low frontal hairline
Eye issues: strabismus, widely spaced eyes, ptosis (upper eyelid is lower than usual)
Involuntary spasms of the eyelids/brows
Small round and/or low-set ears/narrow ear canals
Underdeveloped midface area (creating a malocclusion and/or misalignment of the upper and lower jaws/teeth)
Prominent nose, pointed and/or curved nasal ridge, depressed nasal bridge
Nasal deviated septum (fused bone in upper nasal area)
Presence of a high and narrow palate (roof of mouth is arched)
Shortened fingers or toes, curving of the pinkie finger
Webbing or fusion of the fingers; involving soft parts or the bony structure as well
Most always typical intelligence

Occasional and less common symptoms may include:

Increased intracranial pressure (rise of pressure inside skull)
Short stature
Non-typical hair pattern
Amblyopia (wandering eyes), closely spaced eyes
Conductive hearing loss
Cleft Palate (opening in roof of mouth)
Heart defects
Spine malformations of the vertebra/Scoliosis
Intellectual disability

*Surgical intervention may include cranial vault and midface distraction procedures to improve functions early on, as well as other necessary procedures as the child grows.

how rare is Saethre-Chotzen syndrome?

This syndrome is estimated to occur once in every 50,000 births.

are kids born with this syndrome?

Yes, SCS is a congenital syndrome often apparent at birth. The inheritance is an autosomal dominant pattern, which means the condition has a 50 percent chance of being passed from a positive parent to a child. Some cases of this syndrome are inherited while others are spontaneous new occurrences for the first time in a family.

what is the life expectancy of someone with Saethre-Chotzen?

Even though surgeries may often be in their future, individuals with this condition should have a typical life span. Early medical management of the craniosynostosis is important for the growth of the child and their brain.

how do I know if my child will be born with this syndrome?

Sometimes when an ultrasound is performed during pregnancy, a doctor may notice non-typical signs which require additional testing, such as in-depth 2D/3D ultrasounds or fetal MRI. After birth, clinical examinations, Magnetic Resonance Imaging (MRI), Computed Tomography (CT) scans and genetic testing can help to diagnose the syndrome.

Since Saethre-Chotzen is an autosomal dominant condition, if one of the parents has the syndrome and knows their gene-causing mutation location, genetic testing may be performed for the fetus to determine if the baby has a positive result as well. A positive parent has a 50 percent chance of passing it on; therefore, genetic counseling is recommended.

what gene(s) are responsible for SCS?

TWIST1/Chromosome 7
- More than 180 mutation changes have been identified in individuals with this condition

do we know what causes the malformations of this syndrome to occur?

SCS is caused by genetic mutation/changes in TWIST1 gene. This gene provides instructions for making a protein that plays an important role in early development. During the development of the embryo, the TWIST1 protein is essential for the formation of bone, muscle and other tissues in the head and face. This protein also plays a role in the early development of the arms and legs. Researchers believe that the TWIST1 protein regulates several genes that are known to be key players in bone formation, including the FGFR2 and RUNX2 genes. Additionally, two mutation changes in the TWIST1 gene are known to cause a very rare but similar condition to SCS, called Sweeney-Cox syndrome.

what are other names for Saethre-Chotzen syndrome?

Acrocephalosyndactyly 3
ACS3
B-HLH DNA binging protein
CRS1
H-twist
SCS
Transcription factor TWIST
Twist basic helix-loop-helix transcription factor 1
Twist Homolog
Twist homolog 1 (acrocephalosyndactyly 3; Saethre-Chotzen syndrome) (Drosophila)
Twist homolog 1 (Drosophila)
TWIST1_HUMAN

what are other craniofacial conditions that are related or associated with SCS?

how do you treat Saethre-Chotzen syndrome?

The treatment is focused on the specific symptoms apparent in each individual since the symptoms vary widely. Several specialties and physicians may be involved throughout the child's life, such as craniofacial and reconstructive, for surgeries to correct skull and facial malformations. Patients may see some or all of the following physician specialties: an otolaryngologist (ENT), audiologist, neurologist/neurosurgeon, ophthalmologist, oral surgeon, dentist and more. Early intervention may be important to ensure that children with this syndrome reach their full potential. Special services and therapies may be beneficial.