Currarino syndrome is a symptomatic triad of anorectal and sacral abnormalities with presacral masses. The syndrome is a hereditary disorder commonly associated with a mutation of the MNX1 gene and caused by defective separation of the ento and neuroectoderm. Causal therapies do not exist.
What is currarino syndrome?
The medical term triad refers to a combination of three symptoms. Curranino syndrome is such a triad of symptoms and is associated with anorectal sacral malformation and a presacral mass. The symptom complex is one of the congenital malformation syndromes and is also called Curranino triad because of its triadic basis. Another synonym is the term ASP association, which refers to the symptomatically affected anoracic, sacral, and presacral structures. In the early 20th century, U.S. surgeon R. L. J. Kennedy first described the symptom triad. The triad of the syndrome was revisited at the end of the same century by pediatric radiologist G. Currarino. He gave the syndrome its name. The prevalence of the disease ranges from one to nine cases per 100,000 people. The most common age of manifestation is early childhood.
Causes
The cause of Currarino syndrome is a genetic one. In 70 percent of cases, the disorder does not occur sporadically but is observed with familial clustering. Inheritance in these cases is autosomal dominant. Etiologically, the syndrome is based on a defective separation of the endoderm and neuroectoderm, which occurs during the embryonic phase. The disease is thought to be heterogeneous. In many cases, mutations are responsible for the defective separation of the embryonic structures. Often these mutations are those in the MNX1 gene at gene locus 7q36.3. This gene codes for a nuclear protein called HB9. This protein is irreplaceable for the activity pancreas and various brain structures. With the mutation, the protein is defective and no longer fulfills its functions.
Symptoms, complaints, and signs
Currarino syndrome is characterized by a triadic complex of clinical symptoms and characteristics. For example, among the most important clinical criteria is anorectal abnormality. In addition to stenosis, an anomaly in this area may include, for example, atresia or fistula. The sacrum at the back of the affected person is also affected by bony sacral defects. Ventral to the sacrum are space-occupying lesions. These space-occupying lesions may be meningocele. Teratomas are also conceivable symptoms. In individual cases, enteric cysts have also been identified as space-occupying lesions. In most cases, an anomaly of the coccyx also occurs. Often, individual areas of the bone are not laid out at all. This phenomenon is referred to as partial agenesis, to which the respective space-occupying lesion lies ventrally. The first vertebra of the sacrum is in most cases not affected by the space-occupying lesion. In almost all cases, the symptoms of the disease manifest themselves immediately after birth. In addition to the above-mentioned symptoms, about 50 percent of affected individuals have a malformation of the spinal cord, which is not recognizable at first glance and occurs as a result of impaired neural ear formation. Chronic constipation may also be present.
Diagnosis and course
The diagnosis of Currarino syndrome is usually made in early infancy. In most cases, sonography is used as the primary diagnostic tool. Molecular genetic analysis may reveal a mutation of the MNX1 gene in the diagnosis. However, since this mutation is by no means present in all patients, it is not a mandatory diagnostic criterion. However, if it can be proven, the diagnosis is considered confirmed. The sonographic findings usually give the physician the first suspicion of the syndrome. This suspicion is corroborated with x-rays or imaging such as magnetic resonance imaging. Radiographs of patients with the Currarino triad show a residual sickle-like sacrum called a “scimitar sign.” Magnetic resonance imaging shows half of affected individuals have a well-hidden spinal dysraphism. When such malformations of the spinal cord are present, further investigation of the tethered cord is indicated.Depending on the severity of the syndrome, some patients may remain asymptomatic into adulthood and for this reason are diagnosed late. The severity of the malformations determines the prognosis in individual cases.
When should you see a doctor?
As a rule, a doctor must be consulted for Currarino syndrome when the affected person suffers from the formation of fistulas. Defects may also occur in the bones, although they are not congenital in every case. If Currarino syndrome is diagnosed, in most cases the patient will be dependent on regular examinations throughout his or her life. Anomalies of the coccyx may also indicate this defect and should be examined in early childhood. Especially in case of pain or restrictions in everyday life, a medical examination and treatment is necessary. Furthermore, many affected persons suffer from constipation, so that a medical examination must also be performed. As a rule, the syndrome can be diagnosed by a pediatrician. Treatment is then carried out through various surgical procedures. Furthermore, the affected person must also undergo regular examinations. If the patient also suffers from psychological complaints due to the anomalies and malformations, psychological treatment should also be initiated.
Treatment and therapy
A causal therapy does not exist for patients with Currarino syndrome. Gene therapies are not applicable to date. However, because they are currently the subject of research, causal treatment may be conceivable in the future. Until a causal therapy is applicable, treatment of the symptom triad is exclusively symptomatic. This symptomatic therapy primarily involves correction of the malformations. The corrective measures usually correspond to surgical interventions. For example, surgical treatment of anal atresia can be performed immediately after birth. This is especially indicated when these symptoms are associated with severe constipation. Surgical intervention must also take place with regard to the space-occupying lesions. This intervention is a surgical resection. The indicated time for such a treatment intervention depends on the size and type of the space-occupying lesion in each individual case. The bony sacral defects of the sacrum cannot be corrected in some cases or can only be partially corrected. In cases of agnesia of the coccyx, symptomatic treatment of the syndrome may include additional reconstructive surgical procedures. Basically, for all symptoms of Currarino syndrome, the urgency of interventions depends on the severity of the triad and thus on the individual case.
Outlook and prognosis
Because Currarino syndrome is a genetic disorder, it cannot be treated in a causal and etiologic manner. For this reason, only the individual symptoms can be limited, and a complete cure cannot be achieved. With the help of surgical interventions, many symptoms can be alleviated. They are performed immediately after birth and thus treat the anal retentions. There are no particular complications and this complaint is usually cured. This also alleviates possible constipation or other discomfort in the abdomen and stomach area. However, the discomfort and deformities of the sacrum cannot be completely alleviated. In this case, surgical interventions are also necessary, whereby the corrections can only be partial. The further course thus also depends very much on the exact manifestation of the complaints. However, if the symptoms of Currarino’s syndrome are not treated, the patient will experience severe restrictions in everyday life and also limited mobility. In some cases, Currarino syndrome may also negatively affect the child’s mental development, so the child and parents may also need psychological treatment.
Prevention
To date, the factors that promote the disturbed separation of the endo- and neuroectoderm have not been conclusively elucidated. For this reason, no specific measures are currently available to prevent Currarino syndrome.
Follow-up
Because Currarino syndrome is a hereditary disease, very few, if any, specific options and measures for direct aftercare are available to the affected individual in most cases.The disease can also not be completely treated in this case. If the patient wishes to have children, genetic counseling can also be performed to prevent the recurrence of Currarino syndrome. Early detection of the disease always has a very positive effect on the further course of the disease. Therefore, a doctor should be contacted at the first symptoms and signs of the disease. The treatment of this disease is primarily done by treating the various malformations. In most cases, surgical interventions are necessary. After such an intervention, the affected person should in any case rest and take care of his or her body. Since not all complaints can be corrected, some patients are dependent on the help and care of their own family or friends. In this context, intensive discussions with the affected person also have a positive effect on the course of Currarino syndrome and can also prevent psychological upsets or depression in the process.
What you can do yourself
Currarino syndrome results from a genetic defect that is hereditary. There are neither conventional nor alternative cures aimed at treating the syndrome causally. Only the symptoms can be treated. As a rule, surgical interventions are required for this purpose, which the patient can at best support indirectly. Persons in whose families Currarino syndrome has already occurred once can seek genetic counseling before starting a family. Currarino syndrome is usually diagnosed in infancy. Many affected children have already undergone more than a dozen operations before the age of ten. This is not only physically enormously exhausting. Often, the child’s mental development also suffers, even though there is no mental retardation. The children cannot develop in an age-appropriate manner simply because of the numerous medical interventions. However, parents can counteract this circumstance with targeted early intervention. In addition, a school should be sought at an early stage that allows the child to attend classes despite constant absences due to illness. After a certain age, the affected children suffer not only physically, but also emotionally. This is especially true when symptoms, such as incontinence, appear, making it even more difficult for them to interact with their peers. Parents should consult a child psychologist early on and also seek support themselves, for example through membership in a self-help group.
