"Sotos Syndrome" – What Is It?
Sotos syndrome is a disease caused by mutations, i.e., genetic changes in the NSD1 gene. It is characterized by a characteristic face shape, developmental delay, and tall stature.
How Is "Sotos Syndrome" Diagnosed?

Suspected Diagnosis
Sotos syndrome is suspected if the following findings are present:
- Characteristic shape of the face (easily recognizable at the age of 1-6 years):
- Broad, prominent forehead with long, narrow head shape (long skull)
- Thinning hair around the temples
- Drooping palpebral fissures
- Reddened cheeks
- Long, narrow face
- Long chin
- Developmental delay:
- Early developmental delay and learning disability
- Mild to severe intellectual retardation
- Tall stature:
- Height and/or head circumference ≥97th percentile
Genetic Diagnostics
The diagnosis of “Sotos syndrome” is confirmed when a mutation, i.e., genetic change, is detected in the NSD1 gene.
What Is the Risk of Cancer?

The risk of cancer is mildly increased and is around 3%. The tumor diseases described to date are ovarian tumors, neuroblastomas and gangliomas (nerve tissue tumors), acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), liver, stomach, testicular, and lung cancer.
In addition to the mildly increased risk of cancer, Sotos syndrome can manifest a variety of symptoms, which are categorized into cardinal symptoms, major symptoms, and associated symptoms.
Cardinal Symptoms
They are present in ≥90% of people with Sotos syndrome.
- Characteristic shape of the face
It is present at birth but most obvious between 1 and 6 years of age. It is characterized by a long, narrow head shape, a broad and prominent forehead, thinning hair around the temples, sloping palpebral fissures, and reddened cheeks. In childhood, a narrow jaw and a long chin also appear. In adulthood, the symptoms are usually less pronounced. - Developmental delay
A developmental delay usually encompasses the motor, language, and cognitive areas. Motor milestones are often reached late, sometimes due to height, weak muscles, and a lack of coordination. The cognitive impairment can be mild or so severe that the affected person cannot lead an independent life. - Tall stature
Tall stature is already present prenatally and is mainly the result of increased growth of the arms and legs. Children with Sotos syndrome are usually born mature and have a height and head circumference ≥97th percentile at birth, with body weight usually in the average range. In childhood and adolescence, patients continue to grow steadily so that there is a constant tall stature ≥97th percentile. Height can only normalize in adulthood. The head circumference usually remains ≥97th percentile even in adulthood.
Major Symptoms
They exist in 15-89% of people with Sotos syndrome.
- Behavioral problems
Autism spectrum disorders, anxiety, aggression, difficulties in group settings, naivety, lack of awareness of social behavior - Advanced bone age
In 75-80% of prepubertal patients - Abnormalities of the heart
In 20% of patients in the form of mild to severe defects - Abnormalities in MRI/CT of the head
In the majority of patients, in the form of dilated cerebrospinal fluid spaces, centrally located changes, reduced brain substance, and structural changes in the cerebellum - Overstretched joints, flat feet
In 20% of patients - Pregnancy toxemia
In 15% of pregnancies - Complications in newborns
Jaundice (65%), weak muscles (75%), and feeding difficulties (70%): Mostly spontaneous normalization; intervention is rarely required - Kidney anomalies
In 15% of patients, mainly in the form of urine reflux from the urinary bladder via the ureters into the renal pelvis - Scoliosis (curvature of the spine)
In 30% of patients rarely requiring surgery - Seizures
Non-febrile seizures occur in 25% of patients in the course of their lives.
Associated Symptoms
The following symptoms may occur in 2-15% of patients:
- Eyes: Corneal curvature, cataracts, farsightedness or nearsightedness, strabismus, eye twitching
- Ears: Chronic middle ear infection, conductive hearing loss
- Skeleton: one-sided tall stature, stiff joints, closed cranial sutures, funnel chest, vertebral body anomalies, fusion of the 2nd and 3rd toe, clubfoot
- Abdomen: constipation, reflux of stomach contents into the esophagus, hernia, umbilical hernia
- Skin, nails, teeth: blood sponges, more or less pigmented skin, underdeveloped nails, undercount of teeth
- Genitals: abdominal testicles, hydrocele, incorrectly opening urethra, constricted foreskin
- Metabolism: excessive calcium levels in the blood, low blood sugar levels in newborns
What Is Known About the Development of "Sotos Syndrome"?

Sotos syndrome is caused by mutations, i.e., genetic changes in the NSD1 gene. This gene codes for the NSD1 protein, which is necessary for reading and replicating our body’s DNA, i.e., the genetic material.
If the NSD1 gene is present in an altered form, the NSD1 protein is also not produced correctly and can no longer fulfill its actual function. This can lead to the incorrect development of various structures in our body.
Sotos syndrome occurs in around one in 14,000 live births and can be passed on from parents to their children. The inheritance is autosomal dominant. In around 95% of cases, however, it is a spontaneous or new mutation, known as a de novo mutation.
Is There Any Form of Treatment Available?

Given the large number of possible manifestations, treatment should always be symptom-oriented and carried out in collaboration with various specialist disciplines.
Diagnosis of " Sotos Syndrome" What's Next?
If you have been diagnosed with this cancer predisposition syndrome, it is important to see a specialist. The following section explains whether cancer screening tests or other measures are needed and how they should be carried out. We also give you some valuable tips on what you can do yourself. If you have any questions, please do not hesitate to contact us or your doctor.
Diagnosis of " Sotos Syndrome" What's Next?
If you have been diagnosed with this cancer predisposition syndrome, it is important to see a specialist. The following section explains whether cancer screening tests or other measures are needed and how they should be carried out. We also give you some valuable tips on what you can do yourself. If you have any questions, please do not hesitate to contact us or your doctor.
Medical Measures for Early Detection

There are currently no standardized screening recommendations. Individuals with Sotos syndrome should be examined by a doctor regularly (e.g., once a year). This examination should include the following:
- Detailed medical history
- Auscultation of the heart
- Blood pressure measurement
- Clinical examination of the spine
- Urine examination
Further examinations and referral to specialists should occur if necessary in the event of abnormalities.
Individuals should be made aware of a mildly increased risk of cancer. Targeted cancer screening is not recommended.
Sotos Syndrome – What You Can Do Yourself
You Should Pay Attention to This
You should consult a doctor when changes occur in the spine or joints. In addition, any limitations or changes in vision and hearing should be noticed and reported to a doctor. You should also consult a doctor if you notice any new abnormalities or complaints.
Further Information
Unfortunately, we are not yet aware of any self-help groups for patients with Sotos syndrome. As soon as we have new information, we will add it here. However, patients can also register for the CPS registry at any time or have this done by their doctors in charge.
Any further questions?
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