No cure is known for 22q11.2 deletion syndrome. Certain individual features are treatable using standard treatments. The key is to identify each of the associated features and manage each using the best available treatments.

For example, in children, it is important that the immune problems are identified early, as special precautions are required regarding blood transfusion and immunization with live vaccines. Thymus transplantation can be used to address absence of the thymus in the rare, so-called "complete" 22q11.2 deletion syndrome. Bacterial infections are treated with antibiotics. Cardiac surgery is often required for congenital heart abnormalities. Hypoparathyroidism causing hypocalcaemia often requires lifelong vitamin D and calcium supplements. Specialty clinics that provide multi-system care allow for individuals with 22q11.2 deletion syndrome to be evaluated for all of their health needs and allow for careful monitoring of the patients. An example of this type of system is the 22q Deletion Clinic at SickKids Hospital in Toronto, Canada, which provides children with 22q11 deletion syndrome ongoing support, medical care and information from a team of health care workers.

Successful management of seizures plays a key role in improving quality of life. Antiepileptic medications are the main therapies for seizures; however, it appears that seizures in this syndrome do not respond well to drugs. In the cases reported in literature, numerous new and old antiepileptic drugs have been tried, but no one drug appears to be more efficacious than others. Therefore, no recommendations can be made regarding the selection of the most appropriate antiepileptic drug. As not all cases of ring chromosome 20 syndrome are the same, different individuals may respond to treatment in different ways.Alternates to antiepileptic drug treatment include the ketogenic diet and vagus nerve stimulation but not epilepsy surgery.

Emanuel Syndrome does not have a cure, but individual symptoms may be treated. Assessments of individual systems, such as the cardiovascular, gastrointestinal, orthopedic, and neurological may be necessary to determine the extent of impairment and options for treatment.

The ketogenic diet is a high fat, low carbohydrate diet reserved for intractable childhood epilepsies. There are no published reports on the use of the ketogenic diet in patients with ring chromosome 20 syndrome. However, its efficacy and safety are well established in other difficult to control epilepsy syndromes.

At the present time, there is no specific treatment that can undo any chromosomal abnormality, nor the genetic pattern seen in people with idic(15). The extra chromosomal material in those affected was present at or shortly after conception, and its effects on brain development began taking place long before the child was born. Therapies are available to help address many of the symptoms associated with idic(15). Physical, occupational, and speech therapies along with special education techniques can stimulate children with idic(15) to develop to their full potential.

In terms of medical management of the symptoms associated with Chromosome 15q11.2-q13.1 Duplication Syndrome, families should be aware that individuals with chromosome 15 duplications may tolerate medications differently and may be more sensitive to side effects for some classes of medications, such as the serotonin reuptake inhibitor type medications (SSRI).

Thus, these should be used with caution and any new medication should be instituted in a controlled setting, with slow titration of levels and with a clear endpoint as to what the expected outcome for treatment is.

There is an increased risk of sudden, unexpected death among children and adults with this syndrome. The full cause is not yet understood but it is generally attributed to SUDEP (Sudden Unexplained Death in Epilepsy).

Medical management of children with Trisomy 13 is planned on a case-by-case basis and depends on the individual circumstances of the patient. Treatment of Patau syndrome focuses on the particular physical problems with which each child is born. Many infants have difficulty surviving the first few days or weeks due to severe neurological problems or complex heart defects. Surgery may be necessary to repair heart defects or cleft lip and cleft palate. Physical, occupational, and speech therapy will help individuals with Patau syndrome reach their full developmental potential. Surviving children are described as happy and parents report that they enrich their lives. The cited study grouped Edwards syndrome, which is sometimes survivable beyond toddlerhood, along with Patau, hence the median age of 4 at the time of data collection.

Treatment of Roberts syndrome is individualized and specifically aimed at improving the quality of life for those afflicted with the disorder. Some of the possible treatments include: surgery for the cleft lip and palate, correction of limb abnormalities (also through surgery), and improvement in prehensile hand grasp development.

There is no ‘standard treatment’ for people with CFND due to the large variations in phenotypic expression. Each patient needs to be assessed and treated based on their specific presentation in order to restore the aesthetic and functional balance.

Surgical corrections for the main symptoms;

- Craniosynostosis correction: The preferred age for this procedure is between 6–9 months of age. Performing this surgery at such an early age can limit the further development of facial asymmetry, if the asymmetry is caused by the craniosynostosis, and prevents prolonged elevated intracranial pressure (ICP). However, the data for the exact risk of an elevated intracranial pressure for patients with CFND is lacking in the published literature. The surgery involves a frontal bone advancement in combination with remodellation of the supraorbital rim.

- Orbital hypertelorism: It is preferred to wait with this treatment until the age of 5–8 years old, after permanent dentition. The procedures that can be performed are the facial bipartition and the box osteotomy. Facial bipartition is the more preferable choice as there are less additional corrections needed, as well as providing a more stable long-term result after treatment. After the correction of the orbitas, the medial corners of the eyes are put more into a horizontal line.

- Nasal deformity correction: The correction of the broad nasal base is simultaneously done with the orbital hypertelorism repair. This is for good alignment of the eyes with the nose for the best aesthetic result. A bifid nose tip will only be treated at the age of 18, when the patient's skeleton has fully matured.

There has been no treatment discovered for Jacobsen Syndrome until now but the Symptoms can be treated. 56% of children with Jacobsen Syndrome have congenital heart problems to keep them in check a baseline evaluation can be made by a paediatric cardiologist by carrying out an electrocardiogram or echocardiogram. Any problems that are found can be treated then.

Almost all affected children are born with a bleeding disorder, monthly CBT may help ease the problem. Consecutively Platelet transfusion and ddAVP can be carried out. Medication that interferes with platelet count should be avoided and oral contraceptive therapy may be considered for women with heavy bleeding during menses.

Children affected with Jacobsen Syndrome have severe to Moderate intellectual disabilities and cognitive impairment. An evaluation by a neuropsychologist or a behaviour specialist like a Psychiatrist or Psychologist can be performed, including brain imaging like MRI or ERP. Then as deemed appropriate intervention programs can be carried through. Music therapy is very beneficial for language development. According to the age, befitting vision and hearing test can aid in fixing problems related cognition. For problems related to behaviour like ADHD, medication or therapy would be required but a combination of both is more effective. An ophthalmologist should be consulted to treat the eye defects. Play and interactive games encourage the child to speak. Habilitiation in children should begin at an early age. A habilitation team includes professionals with special expertise in how disability affects everyday life, health and development. The entire family is supported to help the affected children and their families adjust better.

A team of doctors in Australia have trial tested the drug rapamycin in the treatment of a patient said to have Proteus syndrome and have found it to be an effective remedy. However, the diagnosis of Proteus syndrome in this patient has been questioned by others.

The Proteus syndrome research team in the National Human Genome Research Institute at the United States National Institutes of Health have initiated a Phase 0 dose finding trial with the AKT1 inhibitor ARQ 092, which is being developed by the Arqule Corporation. In earlier tests on tissue and cell samples obtained from patients, ARQ 092 reduced phosphorylation of AKT and downstream targets of AKT in as little as two hours. The Phase 0 trial opened in November 2015 and recruited patients in a study titled "Dose Finding Trial of ARQ 092 in Children and Adults With Proteus Syndrome" This trial is based on in vitro data showing inhibition of AKT1 in cell lines from patients with Proteus syndrome.

There is no cure for this condition. Treatment is supportive and varies depending on how symptoms present and their severity. Some degree of developmental delay is expected in almost all cases of M-CM, so evaluation for early intervention or special education programs is appropriate. Rare cases have been reported with no discernible delay in academic or school abilities.

Physical therapy and orthopedic bracing can help young children with gross motor development. Occupational therapy or speech therapy may also assist with developmental delays. Attention from an orthopedic surgeon may be required for leg length discrepancy due to hemihyperplasia.

Children with hemihyperplasia are thought to have an elevated risk for certain types of cancers. Recently published management guidelines recommend regular abdominal ultrasounds up to age eight to detect Wilms' tumor. AFP testing to detect liver cancer is not recommended as there have been no reported cases of hepatoblastoma in M-CM patients.

Congenital abnormalities in the brain and progressive brain overgrowth can result in a variety of neurological problems that may require intervention. These include hydrocephalus, cerebellar tonsillar herniation (Chiari I), seizures and syringomyelia. These complications are not usually congenital, they develop over time often presenting complications in late infancy or early childhood, though they can become problems even later. Baseline brain and spinal cord MRI imaging with repeat scans at regular intervals is often prescribed to monitor the changes that result from progressive brain overgrowth.

Assessment of cardiac health with echocardiogram and EKG may be prescribed and arrhythmias or abnormalities may require surgical treatment.

Since the symptoms caused by this disease are present at birth, there is no “cure.” The best cure that scientists are researching is awareness and genetic testing to determine risk factors and increase knowledgeable family planning. Prevention is the only option at this point in time for a cure.

There is currently no cure for GAPO syndrome, but some options are available to reduce the symptoms. Nearsightedness, which affects some sufferers of the disease, can be treated by corrective lenses. Unfortunately, optic atrophy as a result of degradation of the optic nerve (common with GAPO syndrome) cannot be corrected. Corticosteroids have been proposed as a treatment for optic nerve atrophy, but their effectiveness is disputed, and no steroid based treatments are currently available.

The genetic variation is irreversible, however, individuals who want to look more masculine can take testosterone. Treating adolescents with implants of controlled release testosterone has shown good results when appropriately monitored. Hormone therapy is also useful in preventing the onset of osteoporosis.

Often individuals that have noticeable breast tissue or hypogonadism experience depression and/or social anxiety because they are outside of social norms. An academic term for this is psychosocial morbidity. At least one study indicates that planned and timed support should be provided for young men with Klinefelter syndrome to ameliorate current poor psychosocial outcomes. The surgical removal of the breasts may be considered for both the psychological reasons and to reduce the risk of breast cancer.

The use of behavioral therapy can mitigate any language disorders, difficulties at school and socialization. An approach by occupational therapy is useful in children, especially those who have dyspraxia.

There are several different surgical techniques for the removal of acoustic neuroma. The choice of approach is determined by size of the tumour, hearing capability, and general clinical condition of the patient.

- The retrosigmoid approach offers some opportunity for the retention of hearing.

- The translabyrinthine approach will sacrifice hearing on that side, but will usually spare the facial nerve. Post-operative cerebrospinal fluid leaks are more common.

- The middle fossa approach is preferred for small tumours, and offers the highest probability of retention of hearing and vestibular function.

- Less invasive endoscopic techniques have been done outside of the United States for some time. Recovery times are reported to be faster. However, this technique is not yet mainstream among surgeons in the US.

Larger tumors can be treated by either the translabyrinthine approach or the retrosigmoid approach, depending upon the experience of the surgical team. With large tumors, the chance of hearing preservation is small with any approach. When hearing is already poor, the translabyrinthine approach may be used for even small tumors. Small, lateralized tumours in patients with good hearing should have the middle fossa approach. When the location of the tumour is more medial a retrosigmoid approach may be better.

Auditory canal decompression is another surgical technique that can prolong usable hearing when a vestibular schwannoma has grown too large to remove without damage to the cochlear nerve. In the IAC (internal auditory canal) decompression, a middle fossa approach is employed to expose the bony roof of the IAC without any attempt to remove the tumor. The bone overlying the acoustic nerve is removed, allowing the tumour to expand upward into the middle cranial fossa. In this way, pressure on the cochlear nerve is relieved, reducing the risk of further hearing loss from direct compression or obstruction of vascular supply to the nerve.

Radiosurgery is a conservative alternative to cranial base or other intracranial surgery. With conformal radiosurgical techniques, therapeutic radiation focused on the tumour, sparing exposure to surrounding normal tissues. Although radiosurgery can seldom completely destroy a tumor, it can often arrest its growth or reduce its size. While radiation is less immediately damaging than conventional surgery, it incurs a higher risk of subsequent malignant change in the irradiated tissues, and this risk in higher in NF2 than in sporadic (non-NF2) lesions.

Prader–Willi syndrome has no cure; however, several treatments are in place to lessen the condition's symptoms. During infancy, subjects should undergo therapies to improve muscle strength. Speech and occupational therapy are also indicated. During the school years, children benefit from a highly structured learning environment as well as extra help. The largest problem associated with the syndrome is severe obesity. Access to food must be strictly supervised and limited, usually by installing locks on all food-storage places including refrigerators.

Because hypotonia can be a symptom of PWS, it is vital to provide proper nutrition during infancy. It is also very important to stress physical activity in individuals with PWS for all ages in order to optimize strength and promote a healthy lifestyle.

Prescription of daily recombinant growth hormone injections are indicated for children with PWS. GH supports linear growth and increased muscle mass, and may lessen food preoccupation and weight gain.

Because of severe obesity, obstructive sleep apnea is a common sequela, and a positive airway pressure machine is often needed. There may come a time when a person who has been diagnosed with PWS may have to undergo surgical procedures. One surgery that has proven to be unsuccessful for treating the obesity is gastric bypass. Patients with Prader–Willi syndrome have a very high tolerance to pain; therefore they may be experiencing significant abdominal symptoms such as acute gastritis, appendicitis, or cholecystitis and not be aware of it until later.

Behavior and psychiatric problems should be detected early for the best results. These issues are best when treated with parental education and training. Sometimes medication is introduced as well. Serotonin agonists have been most effective in lessening temper tantrums and improving compulsivity.

Early diagnosis allows better planning of therapy in young patients with NF II. In many cases, the hearing loss is present for 10 years before the correct diagnosis is established. Early in the condition, surgery for an acoustic neurinoma can protect facial nerve function in many patients. In selected cases of patients with very small tumors and good bilateral hearing, surgery may offer the possibility of long-term hearing preservation.

Patients with the Wishard phenotype suffer multiple recurrences of the tumour after surgical treatment. In the case of facial nerve palsy, the muscles of the eyelids can lose their mobility, leading to conjunctivitis and corneal injury. "Lidloading" (implantation of small magnets, gold weights, or springs in the lid) can help prevent these complications. Other means of preserving corneal health include tarsorrhaphy, where the eyelids are partially sewn together to narrow the opening of the eye, or the use of punctal plugs, which block the duct that drains tears from the conjunctival sac. All these techniques conserve moisture from the lacrymal glands, which lubricates the cornea and prevents injury. Most patients with NF II develop cataracts, which often require replacement of the lens. Children of affected parents should have a specialist examination every year to detect developing tumors. Learning of sign language is one means of preparation for those that will most probably suffer complete hearing loss.

Most fetuses with triploidy do not survive to birth, and those that do usually pass within days. As there is no treatment for Triploidy, palliative care is given if a baby survives to birth. If Triploidy is diagnosed during the pregnancy, termination is often offered as an option due to the additional health risks for the mother (preeclampsia, a life-threatening condition, or choriocarcinoma, a type of cancer). Should a mother decide to carry until term or until a spontaneous miscarriage occurs, doctors will monitor her closely in case either condition develops.

Mosaic triploidy has an improved prognosis, but affected individuals have moderate to severe cognitive disabilities.

Since tetrasomy 9p is not usually inherited, the risk of a couple having a second child with the disorder is minimal. While patients often do not survive to reproductive age, those who do may or may not be fertile. The risk of a patient's child inheriting the disorder is largely dependent on the details of the individual's case.

1. Clinical Genetics and Genetic Testing

Genetic testing is necessary to confirm the diagnosis of PMS. A prototypical terminal deletion of 22q13 can be uncovered by karyotype analysis, but many terminal and interstitial deletions are too small to detect with this method. Chromosomal microarray should be ordered in children with suspected developmental delays or ASD. Most cases will be identified by microarray; however, small variations in genes might be missed. The falling cost for whole exome sequencing may replace DNA microarray technology for candidate gene evaluation. Biological parents should be tested with fluorescence "in situ" hybridization (FISH) to rule out balanced translocations or inversions. Balanced translocation in a parent increases the risk for recurrence and heritability within families (figure 3).

Clinical genetic evaluations and dysmorphology exams should be done to evaluate growth, pubertal development, dysmorphic features (table 1) and screen for organ defects (table 2)

2. Cognitive and Behavioral Assessment

All patients should undergo comprehensive developmental, cognitive and behavioral assessments by clinicians with experience in developmental disorders. Cognitive evaluation should be tailored for individuals with significant language and developmental delays. All patients should be referred for specialized speech/language, occupational and physical therapy evaluations.

3. Neurological Management

Individuals with PMS should be followed by a pediatric neurologist regularly to monitor motor development, coordination and gait, as well as conditions that might be associated with hypotonia. Head circumference should be performed routinely up until 36 months. Given the high rate of seizure disorders (up to 41% of patients) reported in the literature in patients with PMS and its overall negative impact on development, an overnight video EEG should be considered early to rule out seizure activity. In addition, a baseline structural brain MRI should be considered to rule out the presence of structural abnormalities.

4. Nephrology

All patients should have a baseline renal and bladder ultrasonography and a voiding cystourethrogram should be considered to rule out structural and functional abnormalities. Renal abnormalities are reported in up to 38% of patients with PMS. Vesicouretral reflux, hydronephrosis, renal agenesis, dysplasic kidney, polycystic kidney and recurrent urinary tract infections have all been reported in patients with PMS.

5. Cardiology

Congenital heart defects (CHD) are reported in samples of children with PMS with varying frequency (up to 25%)(29,36). The most common CHD include tricuspid valve regurgitation, atrial septal defects and patent ductus arteriousus. Cardiac evaluation, including echocardiography and electrocardiogram, should be considered.

6. Gastroenterology

Gastrointestinal symptoms are common in individuals with PMS. Gastroesophageal reflux, constipation, diarrhea and cyclic vomiting are frequently described.

Table 3: Clinical Assessment Recommendations in Phelan McDermid Syndrome.

Both patients with idic(15) and int dup(15) (together, Dup15q syndrome) feature a distinctive electroencephalography (EEG) signature or biomarker in the form of high amplitude spontaneous beta frequency (12–30 Hz) oscillations. This EEG signature was first noted as a qualitative pattern in clinical EEG readings and was later described quantitatively by researchers at the University of California, Los Angeles and their collaborators within the network of national Dup15q clinics. This group of researchers found that beta activity in children with Dup15q syndrome is significantly greater than that observed in (1) healthy, typically developing children of the same age and (2) children of the same age and IQ with autism not caused by a known genetic disorder (i.e., nonsyndromic ASD). The EEG signature appears almost identical to beta oscillations induced by benzodiazepine drugs that modulate GABA receptors, suggesting that the signature is driven by overexpression of duplicated GABA receptor genes "GABRA5", "GABRB3", and "GABRG3" found on 15q11.2-q13.1. Treatment monitoring and identification of molecular disease mechanisms may be facilitated by this biomarker.

By 2010 over 100 successful pregnancies have been reported using IVF technology with surgically removed sperm material from males with Klinefelter syndrome. Microdissection testicular sperm extraction in adult men with Klinefelter syndrome reported success rates of up to 45%.

Tympanostomy tubes are often needed and often more than one set during the person's childhood. Tonsillectomy is also often done to help with sleep apnea and throat infections. Surgery, however, does not always address the sleep apnea and a continuous positive airway pressure (CPAP) machine may be useful. Physical therapy and participation in physical education may improve motor skills. Evidence to support this in adults, however, is not very good.

Efforts to prevent respiratory syncytial virus (RSV) infection with human monoclonal antibodies should be considered, especially in those with heart problems. In those who develop dementia there is no evidence for memantine, donepezil, rivastigmine, or galantamine.

Plastic surgery has been suggested as a method of improving the appearance and thus the acceptance of people with Down syndrome. It has also been proposed as a way to improve speech. Evidence, however, does not support a meaningful difference in either of these outcomes. Plastic surgery on children with Down syndrome is uncommon, and continues to be controversial. The U.S. National Down Syndrome Society views the goal as one of mutual respect and acceptance, not appearance.

Many alternative medical techniques are used in Down syndrome; however, they are poorly supported by evidence. These include: dietary changes, massage, animal therapy, chiropractics and naturopathy, among others. Some proposed treatments may also be harmful.

Hearing aids or other amplification devices can be useful for language learning in those with hearing loss. Speech therapy may be useful and is recommended to be started around 9 months of age. As those with Down syndrome typically have good hand-eye coordination, learning sign language may be possible. Augmentative and alternative communication methods, such as pointing, body language, objects, or pictures, are often used to help with communication. Behavioral issues and mental illness are typically managed with counseling or medications.

Education programs before reaching school age may be useful. School-age children with Down syndrome may benefit from inclusive education (whereby students of differing abilities are placed in classes with their peers of the same age), provided some adjustments are made to the curriculum. Evidence to support this, however, is not very strong. In the United States, the Individuals with Disabilities Education Act of 1975 requires public schools generally to allow attendance by students with Down syndrome.

Individuals with Down syndrome may learn better visually. Drawing may help with language, speech, and reading skills. Children with Down syndrome still often have difficulty with sentence structure and grammar, as well as developing the ability to speak clearly. Several types of early intervention can help with cognitive development. Efforts to develop motor skills include physical therapy, speech and language therapy, and occupational therapy. Physical therapy focuses specifically on motor development and teaching children to interact with their environment. Speech and language therapy can help prepare for later language. Lastly, occupational therapy can help with skills needed for later independence.

This disease has not been shown to be life-threatening or the cause of death in patients. However, treatment is necessary to maintain a healthy lifestyle.