There is no known cure for microcephaly. Treatment is symptomatic and supportive.

Although there is no cure for 13q deletion syndrome, symptoms can be managed, usually with the involvement of a neurologist, rehabilitation physician, occupational therapist, physiotherapist, psychotherapist, nutritionist, special education professional, and/or speech therapist. If the affected child's growth is particularly slow, growth hormone treatment can be used to augment growth. Plastic surgeries can repair cleft palates, and surgical repair or monitoring by a pediatric cardiologist can manage cardiac defects. Some skeletal, neurological, genitourinary, gastrointestinal, and ophthalmic abnormalities can be definitively treated with surgery. Endocrine abnormalities can often be managed medically. Special educators, speech and occupational therapists, and physiotherapists can help a child develop skills in and out of school.

Currently, the most common form of treatment for SLOS involves dietary cholesterol supplementation. Anecdotal reports indicate that this has some benefits; it may result in increased growth, lower irritability, improved sociability, less self-injurious behaviour, less tactile defensiveness, fewer infections, more muscle tone, less photosensitivity and fewer autistic behaviours. Cholesterol supplementation begins at a dose of 40–50 mg/kg/day, increasing as needed. It is administered either through consuming foods high in cholesterol (eggs, cream, liver), or as purified food grade cholesterol. Younger children and infants may require tube feeding. However, dietary cholesterol does not reduce the levels of 7DHC, cannot cross the blood–brain barrier, and does not appear to improve developmental outcomes. One empirical study found that cholesterol supplementation did not improve developmental delay, regardless of the age at which it began. This is likely because most developmental delays stem from malformations of the brain, which dietary cholesterol cannot ameliorate due to its inability to cross the blood–brain barrier.

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.

HMG-CoA reductase inhibitors have been examined as treatment for SLOS. Given that this catalyzes the rate-limiting step in cholesterol synthesis, inhibiting it would reduce the buildup of toxic metabolites such as 7DHC. Simvastatin is a known inhibitor of HMG-CoA reductase, and most importantly is able to cross the blood–brain barrier. It has been reported to decrease the levels of 7DHC, as well as increase the levels of cholesterol. The increased cholesterol levels are due to simvastatin's effect on the expression of different genes. Simvastatin increases the expression of "DHCR7", likely leading to increased activity of DHCR7. It has also been shown to increase the expression of other genes involved in cholesterol synthesis and uptake. However, these benefits are dependent on the amount of residual cholesterol synthesis. Because some individuals possess less severe mutations and demonstrate some amount of DCHR7 activity, these people benefit the most from simvastatin therapy as they still have a partially functioning enzyme. For individuals that show no residual DCHR7 activity, such as those homozygous for null alleles or mutations, simvastatin therapy may actually be toxic. This highlights the importance of identifying the specific genotype of the SLOS patient before administering treatment. It is still unknown if simvastatin will improve the behavioural or learning deficits in SLOS.

At present, treatment for ring 18 is symptomatic, meaning that the focus is on treating the signs and symptoms of the conditions as they arise. To ensure early diagnosis and treatment, it is suggested that people with ring 18 undergo routine screenings for thyroid, hearing, and vision problems.

At present, treatment for 18p- is symptomatic, meaning that the focus is on treating the signs and symptoms of the conditions as they arise. To ensure early diagnosis and treatment, it is suggested that people with 18p- undergo routine screenings for hearing and vision problems.

Pregnant mothers are advised to take folic acid supplements to reduce risk of iniencephaly by up to 70%. Pregnant mothers are also advised not to take antiepileptic drugs, diuretics, antihistamines, and sulfa drugs, all of which have been associated with increased risk for neural tube defects.

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.

Carbamazepine is at least partly effective at reducing the number or severity of attacks in the majority of PEPD patients. High doses of this drug may be required, perhaps explaining the lack of effect in some individuals. While other anti-epileptic drugs, gabapentin and topiramate, have limited effect in some patients, they have not been shown to be generally effective. Opiate derived analgesics are also largely ineffective, with only sporadic cases of beneficial effect.

There is no standard treatment for hydranencephaly. Treatment is symptomatic and supportive. Hydrocephalus may be treated with surgical treatment of a shunt, which often grants a much better prognosis and greater quality of life.

The prognosis for children with hydranencephaly is generally quite poor. Death often occurs in the first year of life, but other children may live several years.

Medical text identifies that hydranencephalic children simply have only their brain stem function remaining, thus leaving formal treatment options as symptomatic and supportive. Severe hydrocephalus causing macrocephaly, a larger than average head circumference, can easily be managed by placement of a shunt and often displays a misdiagnosis of another lesser variation of cephalic condition due to the blanketing nature of hydrocephalus. Plagiocephaly, the asymmetrical distortion of the skull, is another typical associated condition that is easily managed through positioning and strengthening exercises to prevent torticollis, a constant spasm or extreme tightening of the neck muscles.

Because newborns can breathe only through their nose, the main goal of postnatal treatment is to establish a proper airway. Primary surgical treatment of FND can already be performed at the age of 6 months, but most surgeons wait for the children to reach the age of 6 to 8 years. This decision is made because then the neurocranium and orbits have developed to 90% of their eventual form. Furthermore, the dental placement in the jaw has been finalized around this age.

Since newborns with iniencephaly so rarely survive past childbirth, a standard treatment does not exist.

Affected individuals have a somewhat shortened lifespan. The maximum described lifespan is 67 years. Adults with 13q deletion syndrome often need support services to maintain their activities of daily living, including adult day care services or housing services.

Surgery is an option to correct some of the morphological changes made by Liebenberg Syndrome. Cases exist where surgery is performed to correct radial deviations and flexion deformities in the wrist. A surgery called a carpectomy has been performed on a patient whereby a surgeon removes the proximal row of the carpal bones. This procedure removes some of the carpal bones to create a more regular wrist function than is observed in people with this condition.

Structural nasal deformities are corrected during or shortly after the facial bipartition surgery. In this procedure, bone grafts are used to reconstruct the nasal bridge. However, a second procedure is often needed after the development of the nose has been finalized (at the age of 14 years or even later).

Secondary rhinoplasty is based mainly on a nasal augmentation, since it has been proven better to add tissue to the nose than to remove tissue. This is caused by the minimal capacity of contraction of the nasal skin after surgery.

In rhinoplasty, the use of autografts (tissue from the same person as the surgery is performed on) is preferred. However, this is often made impossible by the relative damage done by previous surgery. In those cases, bone tissue from the skull or the ribs is used. However, this may give rise to serious complications such as fractures, resorption of the bone, or a flattened nasofacial angle.

To prevent these complications, an implant made out of alloplastic material could be considered. Implants take less surgery time, are limitlessly available and may have more favorable characteristics than autografts. However, possible risks are rejection, infection, migration of the implant, or unpredictable changes in the physical appearance in the long term.

At the age of skeletal maturity, orthognathic surgery may be needed because of the often hypoplastic maxilla. Skeletal maturity is usually reached around the age of 13 to 16. Orthognathic surgery engages in diagnosing and treating disorders of the face and teeth- and jaw position.

HPE is not a condition in which the brain deteriorates over time. Although serious seizure disorders, autonomic dysfunction, complicated endocrine disorders and other life-threatening conditions may sometimes be associated with HPE, the mere presence of HPE does not mean that these serious problems will occur or develop over time without any previous indication or warning. These abnormalities are usually recognized shortly after birth or early in life and only occur if areas of the brain controlling those functions are fused, malformed or absent.

Prognosis is dependent upon the degree of fusion and malformation of the brain, as well as other health complications that may be present.

The more severe forms of encephalopathy are usually fatal. This disorder consists of a spectrum of defects, malformations and associated abnormalities. Disability is based upon the degree in which the brain is affected. Moderate to severe defects may cause mental retardation, spastic quadriparesis, athetoid movements, endocrine disorders, epilepsy and other serious conditions; mild brain defects may only cause learning or behavior problems with few motor impairments.

Seizures may develop over time with the highest risk before 2 years of age and the onset of puberty. Most are managed with one medication or a combination of medications. Typically, seizures that are difficult to control appear soon after birth, requiring more aggressive medication combinations/doses.

Most children with HPE are at risk of having elevated blood sodium levels during moderate-severe illnesses, that alter fluid intake/output, even if they have no previous diagnosis of diabetes insipidus or hypernatremia.

Currently, research is focusing on identifying the role of the genes on 18p in causing the signs and symptoms associated with deletions of 18p. This will ultimately enable predictive genotyping.

TGIF-Mutations and deletions of this gene have been associated with holoprosencephaly. Penetrance is incomplete, meaning that a deletion of one copy of this gene is not in and of itself sufficient to cause holoprosencephaly. Ten to fifteen percent of people with 18p- have holoprosencephaly, suggesting that other genetic and environmental facts play a role in the etiology of holoprosencephaly in these individuals.

MRI will help with the diagnosis of structural abnormality of the brain. Genetic testing may also be pursued.

Numerous possible risk factors have been identified, including gestational diabetes, transplacental infections (the "TORCH complex"), first trimester bleeding, and a history of miscarriage. As well, the disorder is found twice as often in female babies. However, there appears to be no correlation between HPE and maternal age.

There is evidence of a correlation between HPE and the use of various drugs classified as being potentially unsafe for pregnant and lactating mothers. These include insulin, birth control pills, aspirin, lithium, thorazine, retinoic acid, and anticonvulsants. There is also a correlation between alcohol consumption and HPE, along with nicotine, the toxins in cigarettes and toxins in cigarette smoke when used during pregnancy.

Olanzapine, as well as several other neuroleptic drugs, have also has been investigated for the control of CINV. A 2007 study demonstrated Olanzapine's successful potential for this use, achieving a complete response in the acute prevention of nausea and vomiting in 100% of patients treated with moderately and highly emetogenic chemotherapy, when used in combination with palonosetron and dexamethasone. Neuroleptic agents are now indicated for rescue treatment and the control of breakthrough nausea and vomiting.

Some studies and patient groups say that the use of cannabinoids derived from cannabis during chemotherapy greatly reduces the associated nausea and vomiting, and enables the patient to eat. Synthesized tetrahydrocannabinol (also one of the main active substances in marijuana) is marketed as Marinol and may be practical for this application. Natural medical cannabis is also used and recommended by some oncologists, though its use is regulated and it is not legal in all jurisdictions. However, Marinol was less effective than megestrol acetate in helping cancer patients regain lost appetites. A phase III study found no difference in effects of an oral cannabis extract or THC on appetite and quality of life (QOL) in patients with cancer-related anorexia-cachexia syndrome (CACS) to placebo.

Dexamethasone, a corticosteroid, is often used alongside other antiemetic drugs, as it has synergistic action with many of them, although its specific antiemetic mechanism of action is not fully understood. Metoclopramide, a dopamine D receptor antagonist with possible other mechanisms, is an older drug that is sometimes used, either on its own or in combination with others. Histamine blockers such as diphenhydramine or meclozine may be used in rescue treatment. Lorazepam and diazepam may sometimes be used to relieve anxiety associated with CINV before administration of chemotherapy, and are also often used in the case of rescue treatment.

More than 80% of children with Patau syndrome die within the first year of life. Children with the mosaic variation are usually affected to a lesser extent. In a retrospective Canadian study of 174 children with trisomy 13, median survival time was 12.5 days. One and ten year survival was 19.8% and 12.9% respectively.

Ethmocephaly is a type of cephalic disorder caused by holoprosencephaly. Ethmocephaly is the least common facial anomaly. It consists of a proboscis separating narrow-set eyes with an absent nose and microphthalmia (abnormal smallness of one or both eyes). Cebocephaly, another facial anomaly, is characterized by a small, flattened nose with a single nostril situated below incomplete or underdeveloped closely set eyes.

The least severe in the spectrum of facial anomalies is the median cleft lip, also called premaxillary agenesis.

Although the causes of most cases of holoprosencephaly remain unknown, some may be due to dominant or chromosome causes. Such chromosomal anomalies as trisomy 13 and trisomy 18 have been found in association with holoprosencephaly, or other neural tube defects. Genetic counseling and genetic testing, such as amniocentesis, is usually offered during a pregnancy if holoprosencephaly is detected. The recurrence risk depends on the underlying cause. If no cause is identified and the fetal chromosomes are normal, the chance to have another pregnancy affected with holoprosencephaly is about 6%.

There is no treatment for holoprosencephaly and the prognosis for individuals with the disorder is poor. Most of those who survive show no significant developmental gains. For children who survive, treatment is symptomatic. It is possible that improved management of diabetic pregnancies may help prevent holoprosencephaly, however there is no means of primary prevention.

It is important that parents and caretakers remain calm, take first aid measures, and carefully observe the child. If a child is having a febrile seizure, parents and caregivers should do the following:

- Note the start time of the seizure. If the seizure lasts longer than 5 minutes, call an ambulance. The child should be taken immediately to the nearest medical facility for diagnosis and treatment.

- Call an ambulance if the seizure is less than 5 minutes but the child does not seem to be recovering quickly.

- Gradually place the child on a protected surface such as the floor or ground to prevent accidental injury. Do not restrain or hold a child during a convulsion.

- Position the child on his or her side or stomach to prevent choking. When possible, gently remove any objects from the child’s mouth. Nothing should ever be placed in the child's mouth during a convulsion. These objects can obstruct the child's airway and make breathing difficult.

- Seek immediate medical attention if this is the child’s first febrile seizure and take the child to the doctor once the seizure has ended to check for the cause of the fever. This is especially urgent if the child shows symptoms of stiff neck, extreme lethargy, or abundant vomiting, which may be signs of meningitis, an infection over the brain surface.

In those who have prolonged seizures intravenous lorazepam is recommended. The other benzodiazepines—midazolam and diazepam—are also reasonable options.

5-HT receptor antagonists are very effective antiemetics and constitute a great advance in the management of CINV. These drugs block one or more of the nerve signals that cause nausea and vomiting. During the first 24 hours after chemotherapy, the most effective approach appears to be blocking the 5-HT nerve signal. Approved 5-HT inhibitors include dolasetron (Anzemet), granisetron (Kytril, Sancuso), and ondansetron (Zofran). Their antiemetic effect due to blockade of 5HT3 receptor on vagal afferent in the gut. in addition they also block 5-HT3 receptors in CTZ and STN. The newest 5-HT inhibitor, palonosetron (Aloxi), also prevents delayed nausea and vomiting, which can occur during the 2–5 days after treatment. Since some patients have trouble swallowing pills, these drugs are often available by injection, as orally disintegrating tablets, or as transdermal patches.