C syndrome (Opitz trigonocephaly syndrome)



What is C syndrome?

C syndrome, also known as Opitz trigonocephaly syndrome, is a rare disorder transmitted as a result of “gonadal mosaicism”. Mosaicism refers to a condition in which a person has cells that differ from each other in genetic makeup. The difference is usually a variation in the number of chromosomes. Normally, all body cells would have 46 chromosomes, but in mosaicism, some cells may have 45 or 47. Mosaicism occurs as a result of an error in cell division very early in fetal development.

Trigonocephaly Syndrome is characterized by the child being born with various malformations and deformities of which the most prominent is a triangular shaped head which is caused due to premature closure of skull bones.

How common is C syndrome?

C syndrome is a very rare disorder that seems to affect males and females in equal numbers. Only about 70 cases have been reported in the world’s medical literature. Please discuss with your doctor for further information.


What are the symptoms of C syndrome?

Common signs and symptoms of C syndrome include:

  • Trigonocephaly- a condition in which the skull is a triangular shape caused by premature closure of the bones
  • Distinct face in which the nasal bridge is broad with a short nose
  • Vertical folds over the inner corners of the eyes (epicanthus)
  • Deeply furrowed palate in the mouth
  • Abnormalities of the outer ear
  • Crossed eyes (strabismus)
  • Joints that may be bent in a fixed position or dislocated
  • Loose skin a

Epicanthus, retardation, loss of muscle tone, abnormalities of the sternum, facial palsy, webbed fingers and/or toes, short limbs, heart defects, failure of one or both testicles to move down into the scrotum (cryptorchidism), abnormalities of the kidneys and lungs, deformity of the lower jaw and/or seizures may also be found in individuals with C syndrome.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you or your loved one has any signs or symptoms listed above or you have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes C syndrome?

Gonadal mosaicism is the root cause of Trigonocephaly Syndrome. The exact gene which results in the abnormal cell division and to which chromosome is it associated with is still not known and research is still ongoing as to find out the gene responsible for the development of Trigonocephaly Syndrome.

Risk factors

What increases my risk for C syndrome?

Please consult with your doctor for further information.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is C syndrome diagnosed?

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. Please consult with your doctor for further information.

How is C syndrome treated?

When Trigonocephaly is severe surgery may be performed to relieve the pressure on the brain and cosmetically improve facial appearance. Other treatment is symptomatic and supportive.

Genetic counseling may be of benefit for patients and their families.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage C syndrome?

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: February 27, 2018 | Last Modified: February 6, 2018