What is Saethre-Chotzen Syndrome?
Saethre-Chotzen syndrome is also known as acrocephalosyndactyly type 3 (ACS III).
Closely related to Crouzon syndrome, Saethre-Chotzen syndrome results from an early closing (fusion) of the skull’s side (coronal) sutures or back (lambdoidal) suture. Saethre-Chotzen syndrome occurs with a frequency of one in 25,000-50,000 live births.
Saethre-Chotzen syndrome was named for both individuals who separately reported it in the early 1930s. Haakon Saethre, a Norwegian psychiatrist, documented the similar features of a mother and her two daughters. All three individuals had low-set hairlines, uneven facial features, short fingers, webbing of the second and third fingers, and webbing of the second and third toes. Approximately one year later, German psychiatrist, F. Chotzen, wrote about a father and two sons with similar features, as well as additional characteristics including hearing and mental impairments. Although it was first described nearly 80 years ago, Saethre-Chotzen was only recognized as a distinct syndrome in the 1980s.
Saethre-Chotzen Syndrome Characteristics
Individuals with this syndrome are typically characterized by the following differences:
• short head from front-to-back
• tall, asymmetrical head and face
• flat-looking face due to underdeveloped cheekbones, eye sockets and lower jaw
• unevenly positioned, shallowly placed, protruding eyes that may be crossed or wide-set with drooping eyelids
• slightly off-center, beak-shaped, small nose with a deviated septum
• small, low-set, unusually shaped ears
• low-set hairline
Additional characteristics that may be present include:
• cleft palate
• visual disturbances related to an imbalance or absence of the muscle that moves the eyes
• compromised sound conduction and hearing loss – nasal airway obstruction
• webbing of the fingers and/or toes (in approximately one-third of cases)
• short fingers and toes, with broad thumbs and big toes
• growth delays, leading to less than average adult stature
What is the Cause of Saethre-Chotzen Syndrome?
A baby’s skull is comprised of separate bones connected by sutures, rather than fused bone. These sutures allow the skull to expand as the brain grows. If any (or all) of these sutures close prematurely, the skull cannot grow/form as it usually would, resulting in what is known as craniosynostosis.
In the case of a craniosynostosis-related syndrome, current research points to problems in the genes responsible for producing proteins to regulate cell growth rate and/or cell growth limits. Saethre-Chotzen, Apert, Carpenter, Crouzon, Muenke, and Pfeiffer syndromes fall into this craniosynostosis-related category.
Saethre-Chotzen is the result of a mutation in a gene known at TWIST1 which plays a key role in early development of the skull, face and limbs. Chromosome 7 contains the TWIST1 gene. In a few cases, Saethre-Chotzen syndrome is caused by a structural chromosomal abnormality in the region of chromosome 7.
The cause of Saethre-Chotzen syndrome is a gene alteration, which is sporadic. There is no connection between anything the mother did (or didn’t do) to cause her baby to have Saethre-Chotzen syndrome. If neither parent has Saethre-Chotzen syndrome, their chances of having another child with Saethre-Chotzen is minimal. If a parent has Saethre-Chotzen syndrome, the chances that one or all of his/her children will have it are approximately 50 percent.
Often, Saethre-Chotzen is found within several generations of a family. However, because the symptoms may be minor, it can go undetected in some family members.
Saethre-Chotzen Syndrome Treatment
When a child is born with a craniofacial issue, we evaluate many factors in order to develop the most effective treatment plan. We study how the child’s underlying structures and functions are affected, including: the brain and facial skeleton, the central nervous system, the senses and parts of the spine (cervical vertebrae). In patients whose facial skeleton is affected, we carefully identify resulting changes in the soft tissues of the face, mouth and top of throat (pharynx). It’s imperative to quickly determine how their condition is affecting normal, critical functions such as breathing, swallowing and speaking, so that we can promptly begin appropriate treatment.
In most syndromes, the abnormal growth patterns continue throughout the growing years because they were programmed into the body while the embryo was forming. In order to correct and repair the child’s areas of concern, we evaluate the anatomical and functional problems and carry the treatment plan out in stages. At each new level of maturity, we’ll take advantage of the natural windows of opportunity for reconstruction and other surgical procedures.
We must time each intervention carefully, because when we change or correct part of a child’s body, that surgery indirectly affects the body’s growth and development “messages.” Our broad range of experience allows us to not only identify the most appropriate timing for repairs but to also respond to unpredictable changes as we go.
Essential factors will lead to the best outcome: For our part, accurate diagnosis and a customized, expertly carried-out treatment plan are primary concerns. This applies to reconstructive surgery, as well as aesthetic surgery, to create the very best facial and corporal appearance. For your part, as the parent/family, the outcome depends on your commitment to play the key support role throughout the child’s various surgeries, physical changes, social adaptations, academic development and everyday life skills.
In all syndrome conditions, our treatment goals fall into similar categories – to give the child’s brain and all sensory organs room to grow and develop, and to make it as easy as possible for the child to breathe, eat, sleep, communicate and become as independent as possible.
Treatment may include surgical release of any fused skull sutures, facial advancement, eye surgery, staged orthodontics, and possibly palatal closure, nasal reconstruction and speech therapy.