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.

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.

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.

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.

The treatment of individuals with TCS may involve the intervention of professionals from multiple disciplines. The primary concerns are breathing and feeding, as a consequence of the hypoplasia of the mandibula and the obstruction of the hypopharynx by the tongue. Sometimes, they may require a tracheostomy to maintain an adequate airway, and a gastrostomy to assure an adequate caloric intake while protecting the airway. Corrective surgery of the face is performed at defined ages, depending on the developmental state.

An overview of the present guidelines:

- If a cleft palate is present, the repair normally takes place at 9–12 months old. Before surgery, a polysomnography with a palatal plate in place is needed. This may predict the postoperative situation and gives insight on the chance of the presence of sleep apnea (OSAS) after the operation.

- Hearing loss is treated by bone conduction amplification, speech therapy, and educational intervention to avoid language/speech problems. The bone-anchored hearing aid is an alternative for individuals with ear anomalies

- Zygomatic and orbital reconstruction is performed when the cranio-orbitozygomatic bone is completely developed, usually at the age of 5–7 years. In children, an autologous bone graft is mostly used. In combination with this transplantation, lipofilling can be used in the periorbital area to get an optimal result of the reconstruction. Reconstruction of the lower eyelid coloboma includes the use of a myocutaneous flap, which is elevated and in this manner closes the eyelid defect.

- External ear reconstruction is usually done when the individual is at least eight years old. Sometimes, the external auditory canal or middle ear can also be treated.

- The optimal age for the maxillomandibular reconstruction is controversial; as of 2004, this classification has been used:

1. Type I (mild) and Type IIa (moderate) 13–16 years

2. Type IIb (moderate to severe malformation) at skeletal maturity

3. Type III (severe) 6–10 years

- When the teeth are cutting, the teeth should be under supervision of an orthodontist to make sure no abnormalities occur. If abnormalities like dislocation or an overgrowth of teeth are seen, appropriate action can be undertaken as soon as possible.

- Orthognatic treatments usually take place after the age of 16 years; at this point, all teeth are in place and the jaw and dentures are mature. Whenever OSAS is detected, the level of obstruction is determined through endoscopy of the upper airways. Mandibular advancement can be an effective way to improve both breathing and æsthetics, while a chinplasty only restores the profile.

- If a nose reconstruction is necessary, it is usually performed after the orthognatic surgery and after the age of 18 years.

- The contour of the facial soft tissues generally requires correction at a later age, because of the facial skeletal maturity. The use of microsurgical methods, like the free flap transfer, has improved the correction of facial soft tissue contours. Another technique to improve the facial soft tissue contours is lipofilling. For instance, lipofilling is used to reconstruct the eyelids.

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.

The general prognosis for girls with tetrasomy X is relatively good. Due to the variability of symptoms, some tetrasomy X girls are able to function normally, whereas others will need medical attention throughout their lives. Traditionally, treatment for tetrasomy X has been management of the symptoms and support for learning. Most girls are placed on estrogen treatment to induce breast development, arrest longitudinal growth, and stimulate bone formation to prevent osteoporosis. Speech, occupational, and physical therapy may also be needed depending on the severity of the symptoms.

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.

The disorder can be associated with a number of psychological symptoms, anxiety, depression, social phobia, body image disorders, and patients may be subjected to discrimination, bullying and name calling especially when young. A multi-disciplinary team and parental support should include these issues.

Edwards syndrome, also known as trisomy 18, is a genetic disorder caused by the presence of all, or part of a third copy of chromosome 18. Many parts of the body are affected. Babies are often born small and have heart defects. Other features include a small head, small jaw, clenched fists with overlapping fingers, and severe intellectual disability.

Most cases of Edwards syndrome occur due to problems during the formation of the reproductive cells or during early development. The rate of disease increases with the mother's age. Rarely cases may be inherited from a person's parents. Occasionally not all cells have the extra chromosome, known as mosaic trisomy, and symptoms in these cases may be less severe. Ultrasound can increase suspicion for the condition, which can be confirmed by amniocentesis.

Treatment is supportive. After having one child with the condition, the risk of having a second is typically around one percent. It is the second-most frequent condition due to a third chromosome at birth, after Down syndrome.

Edwards syndrome occurs in around one in 5,000 live births. Some studies suggest that more babies that survive to birth are female. Many of those affected die before birth. Survival beyond a year of life is around 5-25%. It is named after John Hilton Edwards, who first described the syndrome in 1960.

In 2008/2009, 495 diagnoses of Edwards syndrome (trisomy 18) were made in England and Wales, 92% of which were made prenatally, resulting in 339 abortions, 49 stillbirths/miscarriages/fetal deaths, 72 unknown outcomes, and 35 live births. Because about 3% of cases with unknown outcomes are likely to result in a live birth, the total number of live births is estimated to be 37 (2008/09 data are provisional). Major causes of death include apnea and heart abnormalities. It is impossible to predict an exact prognosis during pregnancy or the neonatal period. Half of the infants with this condition do not survive beyond the first week of life. The median lifespan is five to 15 days. About 8-12% of infants survive longer than 1 year. One percent of children live to age 10, though a retrospective Canadian study of 254 children with trisomy 18 demonstrated ten year survival of 9.8%.

As of 2017, data on optimal treatment was limited. Therapies with hormones is the standard of care, namely adrenocorticotrophic hormone (ACTH), or oral

corticosteroids such as prednisone. Vigabatrin is also a common consideration, though there is a risk of visual field loss with long term use. The high cost of ACTH leads doctors to avoid it in the US; higher dose prednisone appears to generate equivalent outcomes.

As of 2017 data from clinical trials of the ketogenic diet for treating infantile spams was inconsistent; most trials were as a second-line therapy after failure of drug treatment, and as of 2017 it had not been explored as a first line treatment in an adequately designed clinical trial.

Most affected people have a stable clinical course but are often transfusion dependent.

Derivative 22 syndrome, or der(22), is a rare disorder associated with multiple congenital anomalies, including profound mental retardation, preauricular skin tags or pits, and conotruncal heart defects. It can occur in offspring of carriers of the constitutional chromosomal translocation t(11;22)(q23;q11), owing to a 3:1 meiotic malsegregation event resulting in partial trisomy of chromosomes 11 and 22. An unbalanced translocation between chromosomes 11 & 22 is described as Emanuel syndrome. It was characterized in 1980.

Young–Madders syndrome, alternatively known as Pseudotrisomy 13 syndrome or holoprosencephaly–polydactyly syndrome, is a genetic disorder resulting from defective and duplicated chromosomes which result in holoprosencephaly, polydactyly, facial malformations and mental retardation, with a significant variance in the severity of symptoms being seen across known cases. Many cases often suffer with several other genetic disorders, and some have presented with hypoplasia, cleft lip, cardiac lesions and other heart defects. In one case in 1991 and another in 2000 the condition was found in siblings who were the product of incest. Many cases are diagnosed prenatally and often in siblings. Cases are almost fatal in the prenatal stage with babies being stillborn.

Though it is now thought that earlier cases were misdiagnosed as other genetic disorders with similar pathology—such as Smith–Lemli–Opitz syndrome—the earliest publicised recognition of the condition as a new, hitherto unclassified, genetic disorder was made by two British doctors in Leicester in 1987. Though they identified the condition, later named for them, they did not identify the genetic anomalies responsible but suspected a link with trisomy 13 due to the similar symptoms. With only one or two occurrences documented towards the end of the decade, a group of eight doctors published a five-patient case-study in 1991 which identified the likely chromosomal factors that caused the condition, similar to but distinct from trisomy 13, and gave it the name 'holoprosencephaly–polydactyly syndrome' based on its two most prolific presenting conditions. Later research showed that the condition could manifest in patients with normal karyotypes, without duplication of the chromosomes, and the most recent genetic research implicates problems with the gene code FBXW11 as a likely cause.

Exposure of spermatozoa to lifestyle, environmental and/or occupational hazards may increase the risk of aneuploidy. Cigarette smoke is a known aneugen (aneuploidy inducing agent). It is associated with increases in aneuploidy ranging from 1.5 to 3.0-fold. Other studies indicate factors such as alcohol consumption, occupational exposure to benzene, and exposure to the insecticides fenvalerate and carbaryl also increase aneuploidy.

Trisomy 8, also known as Warkany syndrome 2, is a human chromosomal disorder caused by having three copies (trisomy) of chromosome 8. It can appear with or without mosaicism.

With the Echidna, this kind of chromosomal arrangement is normal. In this species genetic sex differentiation works like this:

- 63 (XYXYXYXYX, male) and

- 64 (XXXXXXXXXX, female)

Currently there is no curative treatment for KSS. Because it is a rare condition, there are only case reports of treatments with very little data to support their effectiveness. Several promising discoveries have been reported which may support the discovery of new treatments with further research. Satellite cells are responsible for muscle fiber regeneration. It has been noted that mutant mtDNA is rare or undetectable in satellite cells cultured from patients with KSS. Shoubridge et al. (1997) asked the question whether wildtype mtDNA could be restored to muscle tissue by encouraging muscle regeneration. In the forementioned study, regenerating muscle fibers were sampled at the original biopsy site, and it was found that they were essentially homoplasmic for wildtype mtDNA. Perhaps with future techniques of promoting muscle cell regeneration and satellite cell proliferation, functional status in KSS patients could be greatly improved.

One study described a patient with KSS who had reduced serum levels of coenzyme Q10. Administration of 60–120 mg of Coenzyme Q10 for 3 months resulted in normalization of lactate and pyruvate levels, improvement of previously diagnosed first degree AV block, and improvement of ocular movements.

A screening ECG is recommended in all patients presenting with CPEO. In KSS, implantation of pacemaker is advised following the development of significant conduction disease, even in asymptomatic patients.

Screening for endocrinologic disorders should be performed, including measuring serum glucose levels, thyroid function tests, calcium and magnesium levels, and serum electrolyte levels. Hyperaldosteronism is seen in 3% of KSS patients.

Triple X syndrome, also known as trisomy X and 47,XXX, is characterized by the presence of an extra X chromosome in each cell of a female. Those affected are often taller than average. Usually there are no other physical differences and normal fertility. Occasionally there are learning difficulties, decreased muscle tone, seizures, or kidney problems.

Triple X is due to a random event. Triple X can result either during the division of the mother's reproductive cells or during division of cells during early development. It is not typically inherited from one generation to the next. A form where only a percentage of the body cells contain XXX can also occur. Diagnosis is by chromosomal analysis.

Treatment may include speech therapy, physical therapy, and counseling. It occurs in about one in every 1,000 female births. It is estimated that 90% of those affected are not diagnosed as they either have no or only few symptoms. It was first identified in 1959.

No treatment is available to cure or slow down the progression of aspartylglucosaminuria. Bone marrow transplants have been conducted in hope that the bone marrow will produce the missing enzyme. The results of the tests thus far have shown to be inconclusive.

Since ear infections and respiratory infections are common for children diagnosed with aspartylglucosaminuria, it is best to have regular checkups for both the ears and the respiratory tract.

Extreme sensitivity to the sun’s rays may develop; the best way to protect an individual diagnosed with aspartylglucosaminuria is to have them wear sunglasses, hats or caps to protect their eyes.

Epilepsy and insomnia can both be treated with medication.

It will be beneficial to children who are diagnosed with AGU to receive an education from a school with special teaching.

The duplication involved in PTLS is usually large enough to be detected through G-banding alone, though there is a high false negative rate. To ascertain the diagnosis when karyotyping results are unclear or negative, more sophisticated techniques such as subtelomeric fluorescent in-situ hybridization analysis and array comparative genomic hybridization (aCGH) may be used.

Potocki–Lupski syndrome (PTLS), also known as dup(17)p11.2p11.2 syndrome, trisomy 17p11.2 or duplication 17p11.2 syndrome, is a contiguous gene syndrome involving the microduplication of band 11.2 on the short arm of human chromosome 17 (17p11.2). The duplication was first described as a case study in 1996. In 2000, the first study of the disease was released, and in 2007, enough patients had been gathered to complete a comprehensive study and give it a detailed clinical description. PTLS is named for two researchers involved in the latter phases, Drs. Lorraine Potocki and James R. Lupski of Baylor College of Medicine.

PTLS was the first predicted of a homologous recombination (microdeletion or microduplication) where both reciprocal recombinations result in a contiguous gene syndrome. Its reciprocal disease is Smith–Magenis syndrome (SMS), in which the chromosome portion duplicated in PTLS is deleted altogether.

Potocki–Lupski syndrome is considered a rare disease, predicted to appear in at least 1 in 20,000 humans.

Symptoms of the syndrome include intellectual disability, autism, and other disorders unrelated to the listed symptoms.

Young–Madders syndrome is detectable from the fetal stage of development largely due to the distinctive consequences of holoprosencephaly, a spectrum of defects or malformations of the brain and face. Facial defects which may manifest in the eyes, nose, and upper lip, featuring cyclopia, anosmia, or in the growth of only a single central incisor, and severe overlapping of the bones of the skull. Cardiac and in some cases pulmonary deformities are present. Another signature deformity is bilateral polydactyly, and many patients also suffer from hypoplasia and genital deformities.