Surgery is typically used to correct structural heart defects and syndactyly. Propanolol or beta-adrenergic blockers are often prescribed as well as insertion of a pacemaker to maintain proper heart rhythm. With the characterization of Timothy syndrome mutations indicating that they cause defects in calcium currents, it has been suggested that calcium channel blockers may be effective as a therapeutic agent.

At the 2005 American Society of Human Genetics meeting, Francis Collins gave a presentation about a treatment he devised for children affected by Progeria. He discussed how farnesyltransferase inhibitor (FTI) affects H-Ras. After his presentation, members of the Costello Syndrome Family Network discussed the possibility of FTIs helping children with Costello syndrome. Mark Kieran, who presented at the 1st International Costello Syndrome Research Symposium in 2007, agreed that FTIs might help children with Costello syndrome. He discussed with Costello advocates what he had learned in establishing and running the Progeria clinical trial with an FTI, to help them consider next steps.

Another medication that affects H-Ras is Lovastatin, which is planned as a treatment for neurofibromatosis type I. When this was reported in mainstream news, the Costello Syndrome Professional Advisory Board was asked about its use in Costello Syndrome. Research into the effects of Lovastatin was linked with Alcino Silva, who presented his findings at the 2007 symposium. Silva also believed that the medication he was studying could help children with Costello syndrome with cognition.

A third medication that might help children with Costello syndrome is a MEK inhibitor that helps inhibit the pathway closer to the cell nucleus.

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.

As a chromosomal condition, there is no cure for Turner syndrome. However, much can be done to minimize the symptoms. For example:

- Growth hormone, either alone or with a low dose of androgen, will increase growth and probably final adult height. Growth hormone is approved by the U.S. Food and Drug Administration for treatment of Turner syndrome and is covered by many insurance plans. There is evidence that this is effective, even in toddlers.

- Estrogen replacement therapy such as the birth control pill, has been used since the condition was described in 1938 to promote development of secondary sexual characteristics. Estrogens are crucial for maintaining good bone integrity, cardiovascular health and tissue health. Women with Turner Syndrome who do not have spontaneous puberty and who are not treated with estrogen are at high risk for osteoporosis and heart conditions.

- Modern reproductive technologies have also been used to help women with Turner syndrome become pregnant if they desire. For example, a donor egg can be used to create an embryo, which is carried by the Turner syndrome woman.

- Uterine maturity is positively associated with years of estrogen use, history of spontaneous menarche, and negatively associated with the lack of current hormone replacement therapy.

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.

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.

Pancreatic exocrine insufficiency may be treated through pancreatic enzyme supplementation, while severe skeletal abnormalities may require surgical intervention. Neutropenia may be treated with granulocyte-colony stimulating factor (GCSF) to boost peripheral neutrophil counts. However, there is ongoing and unresolved concern that this drug could contribute to the development of leukemia. Signs of progressive marrow failure may warrant bone marrow transplantation (BMT). This has been used successfully to treat hematological aspects of disease. However, SDS patients have an elevated occurrence of BMT-related adverse events, including graft-versus-host disease (GVHD) and toxicity relating to the pre-transplant conditioning regimen. In the long run, study of the gene that is mutated in SDS should improve understanding of the molecular basis of disease. This, in turn, may lead to novel therapeutic strategies, including gene therapy and other gene- or protein-based approaches.

Treatment of Aicardi syndrome primarily involves management of seizures and early/continuing intervention programs for developmental delays.

Additional comorbidities and complications sometimes seen with Aicardi syndrome include porencephalic cysts and hydrocephalus, and gastro-intestinal problems. Treatment for porencephalic cysts and/or hydrocephalus is often via a shunt or endoscopic of the cysts, though some require no treatment. Placement of a feeding tube, fundoplication, and surgeries to correct hernias or other gastrointestinal structural problems are sometimes used to treat gastro-intestinal issues.

There is no medical treatment for either syndrome but there are some recommendations that can help with prevention or early identification of some of the problems. Children with either syndrome should have their hearing tested, and adults should be aware that the hearing loss may not develop until the adult years. Yearly visits to an ophthalmologist or other eye care professional who has been informed of the diagnosis of Stickler or Marshall syndrome is important for all affected individuals. Children should have the opportunity to have myopia corrected as early as possible, and treatment for cataracts or detached retinas may be more effective with early identification. Support for the joints is especially important during sports, and some recommend that contact sports should be avoided by those who have very loose joints.

There is no cure for Williams syndrome. Suggestions include avoidance of extra calcium and vitamin D, as well as treating high levels of blood calcium. Blood vessel narrowing can be a significant health problem, and is treated on an individual basis.

Physical therapy is helpful to patients with joint stiffness and low muscle tone. Developmental and speech therapy can also help children and increase the success of their social interactions. Other treatments are based on a patient's particular symptoms.

The American Academy of Pediatrics recommends annual cardiology evaluations for individuals with Williams syndrome. Other recommended assessments include: ophthalmologic evaluations, an examination for inguinal hernia, objective hearing assessment, blood pressure measurement, developmental and growth evaluation, orthopedic assessments on joints, muscle tone, and ongoing feeding and dietary assessments to manage constipation and urinary problems.

Behavioral treatments have been shown to be effective. In regards to social skills it may be effective to channel their nature by teaching basic skills. Some of these are the appropriate way to approach someone, how and when to socialize in settings such as school or the workplace, and warning of the signs and dangers of exploitation. For the fear that they demonstrate cognitive-behavioral approaches, such as therapy, are the recommended treatment. One of the things to be careful of with this approach is to make sure that the patients' charming nature does not mask any underlying feelings.

Perhaps the most effective treatment for those with Williams syndrome is music. Those with Williams syndrome have shown a relative strength in regards to music, albeit only in pitch and rhythm tasks. Not only do they show a strength in the field but also a particular fondness for it. It has been shown that music may help with the internal and external anxiety that these people are more likely to be afflicted with. Something of note is that the typical person processes music in the superior temporal and middle temporal gyri. Those with Williams syndrome have a reduced activation in these areas but an increase in the right amygdala and cerebellum.

People affected by Williams syndrome are supported by multiple organizations, including the Canadian Association for Williams Syndrome and the Williams Syndrome Registry.

In terms of treatment/management one should observe what signs or symptoms are present and therefore treat those as there is no other current guideline. The affected individual should be monitored for cancer of:

- Thyroid

- Breast

- Renal

Treatments focuses on symptoms, with genetic counseling recommended.

Treatment for Romano–Ward syndrome can "deal with" the imbalance between the right and left sides of the sympathetic nervous system which may play a role in the cause of this syndrome. The imbalance can be temporarily abolished with a left stellate ganglion block, which shorten the QT interval. If this is successful, surgical ganglionectomy can be performed as a permanent treatment.Ventricular dysrhythmia may be managed by beta-adrenergic blockade (propranolol)

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%.

Treatment for the disease itself is nonexistent, but there are options for most of the symptoms. For example, one suffering from hearing loss would be given hearing aids, and those with Hirschsprung’s disorder can be treated with a colostomy.

Many professionals that are likely to be involved in the treatment of those with Stickler's syndrome, include anesthesiologists, oral and maxillofacial surgeons; craniofacial surgeons; ear, nose, and throat specialists, ophthalmologists, optometrists, audiologists, speech pathologists, physical therapists and rheumatologists.

Treatment consists of maintaining normal levels of calcium, phosphorus, and Vitamin D. Phosphate binders, supplementary Calcium and Vitamin D will be used as required.

If a contracture is less than 30 degrees, it may not interfere with normal functioning. The common treatment is splinting and occupational therapy. Surgery is the last option for most cases as the result may not be satisfactory.

The outcome of this disease is dependent on the severity of the cardiac defects. Approximately 1 in 3 children with this diagnosis require shunting for the hydrocephaly that is often a consequence. Some children require extra assistance or therapy for delayed psychomotor and speech development, including hypotonia.

Café au lait spots can be removed with lasers. Results are variable as the spots are often not completely removed or can come back after treatment. Often, a test spot is treated first to help predict the likelihood of treatment success.

Prognoses for 3C syndrome vary widely based on the specific constellation of symptoms seen in an individual. Typically, the gravity of the prognosis correlates with the severity of the cardiac abnormalities. For children with less severe cardiac abnormalities, the developmental prognosis depends on the cerebellar abnormalities that are present. Severe cerebellar hypoplasia is associated with growth and speech delays, as well as hypotonia and general growth deficiencies.

If the Hirschsprung's disease is treated in time, ABCD sufferers live otherwise healthy lives. If it is not found soon enough, death often occurs in infancy. For those suffering hearing loss, it is generally regressive and the damage to hearing increases over time. Digestive problems from the colostomy and reattachment may exist, but most cases can be treated with laxatives. The only other debilitating symptom is hearing loss, which is usually degenerative and can only be treated with surgery or hearing aids.

Spanish researchers reported the development of a Costello mouse, with the G12V mutation, in early 2008. Although the G12V mutation is rare among children with Costello syndrome, and the G12V mouse does not appear to develop tumors as expected, information about the mouse model's heart may be transferrable to humans.

Italian and Japanese researchers published their development of a Costello zebrafish in late 2008, also with the G12V mutation. The advent of animal models may accelerate identification of treatment options.

Pegvisomant is one pharmaceutical drug which has received attention for being a possible treatment route for Gigantism. Reduction of the levels of IGF-I as a result of pegvisomant administration can be incredibly beneficial for the pediatric gigantism patients.

After treatment with pegvisomant, high growth rates, a feature characteristic of gigantism, can be significantly decreased. Pegvisomant has been seen to be a powerful alternative to other treatments such as somatostatin analogues, a common treatment method for acromegaly, if drug treatment is paired with radiation.

Finding the optimal level of pegvisomant is important so normal body growth is not negatively affected. In order to do this, titration of the medication can be used as a way to find the proper administration level.

See acromegaly for additional treatment possibilities.

Harlequin syndrome is not debilitating so treatment is not normally necessary. In cases where the individual may feel socially embarrassed, contralateral sympathectomy may be considered, although compensatory flushing and sweating of other parts of the body may occur. In contralateral sympathectomy, the nerve bundles that cause the flushing in the face are interrupted. This procedure causes both sides of the face to no longer flush or sweat. Since symptoms of Harlequin syndrome do not typically impair a person’s daily life, this treatment is only recommended if a person is very uncomfortable with the flushing and sweating associated with the syndrome.