About trigonocephaly syndrome
What is trigonocephaly 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.
Affected individuals are born with a malformation in which the head is a triangular shape due to premature union of the skull bones (trigonocephaly), a narrow pointed forehead, a flat broad nasal bridge with a short nose, vertical folds over the inner corners of the eyes, an abnormal palate that is deeply furrowed, abnormalities of the ear, crossed eyes (strabismus), joints that are bent or in a fixed position, and loose skin. Developmental and learning disabilities are common.
What are the symptoms for trigonocephaly syndrome?
One of the major features of OTCS is a condition in which the skull is a triangular shape. This occurs due to premature closure of the bones (trigonocephaly or prominent metopic suture due to its premature fusion). Patients with this disorder also have a distinct face in which the nasal bridge is broad with a short nose, there are vertical folds over the inner corners of the eyes (epicanthus) and Paralysis of facial muscles (facial palsy). These children may have abnormalities of the outer ear, crossed eyes (strabismus), thin upper lip, smooth vertical groove between the base of the nose and the border of the upper lip (philtrum),an undersized jaw (micrognathia), a short neck and loose skin. Additional characteristics can include abnormalities of the breastbone (sternum), webbed fingers and/or toes (syndactyly), short limbs, heart, pancreas, kidney and lung abnormalities and failure of one or both testicles to move down into the scrotum (cryptorchidism).
Feeding difficulties may occur because of a deeply furrowed palate in the mouth and malposition of teeth. Additional characteristics can include loss of muscle tone and joints in the hands bent in a fixed position or dislocated.
Affected children may have central nervous system malformations and seizures. Developmental delay (motor, mental or global) and speech delay are common and children with C syndrome have Intellectual disability that can vary from mild to severe.
What are the causes for trigonocephaly syndrome?
There is no common genetic cause for OTCS. Recent research has found that changes (mutations) in specific genes could be associated with this condition: MAGEL2, FOXP1, IFT140 and ASXL3.
Until recently, OTCS was thought to follow an autosomal recessive pattern of inheritance. However, it is now believed that the disorder occurs as a result of de novo dominant heritance or gonadal mosaicism. Mosaicism refers to a condition in which a person has cells that differ from each other in genetic makeup.
Dominant genetic disorders occur when only a single copy of an altered gene is necessary to cause a particular disease. The altered gene can be inherited from an affected parent or can be the result of a new change (mutation) in the affected individual. The risk of passing the altered gene from an affected parent to an offspring is 50% for each pregnancy. The risk is the same for males and females.
What are the treatments for trigonocephaly syndrome?
There is no specific treatment for OTCS but treatment for some symptoms is possible. When trigonocephaly is severe, surgery may be performed to relieve the pressure on the brain and improve facial appearance. Other surgical procedures may be indicated for heart and other malformations. Supportive therapies such as speech therapy and interdisciplinary rehabilitation may be helpful in some patients. Genetic counseling is recommended for patients and their families.
What are the risk factors for trigonocephaly syndrome?
Only about 60 patients with OTCS have been reported in the world’s medical literature. OTCS is a very rare disorder that seems to affect males and females in equal numbers. The prevalence is between 1/800,000 and 1/1,000,000.
Is there a cure/medications for trigonocephaly syndrome?
The complex condition known as trigonocephaly syndrome (OTCS) is associated with a wide variety of clinical characteristics and anomalies. This preliminary diagnosis may be given to children, who may later be found to have a particular genetic disorder.
Affected children are born with trigonocephaly, a malformation characterized by a triangular-shaped head, a narrow pointed forehead, a flat, broad nasal bridge with a short nose, vertical folds over the inner corners of the eyes, an abnormal palate that is deeply furrowed, abnormalities of the ear, crossed eyes (strabismus), joints that are bent or in a fixed position, and loose skin. These symptoms and indicators can differ greatly from patient to patient.
Children who are affected may experience seizures and central nervous system abnormalities. Children with C syndrome frequently experience developmental (motor, mental, or global) and speech delays, and they may also have mild to severe intellectual disability.
Treatment for trigonocephaly syndrome
1. Although there is no treatment or cure for trigonocephaly syndrome, some symptoms may be managed.
2. Surgery may be performed when trigonocephaly is severe to relieve pressure on the brain and enhance facial attractiveness.
3. Indications for additional surgical operations for the heart and other abnormalities may exist.
4. Some patients may benefit from supportive therapies like speech therapy and interdisciplinary rehabilitation.
5. It is advised that patients and their families seek genetic counseling.
Skull in a triangular shape,Abnormalities in the inner corner of eyes,Face paralysis,Thin upper lips, and undersized jawline,Loose skin,Short neck
Difficulty with vision