Lujan–Fryns syndrome is a rare X-linked dominant syndrome, and is therefore more common in males than females. Its prevalence within the general population has not yet been determined.

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.

The syndrome primarily affects young males. Preliminary studies suggest that prevalence may be 1.8 per 10,000 live male births. 50% of those affected do not live beyond 25 years of age, with deaths attributed to the impaired immune function.

The estimated prevalence of Jacobsen syndrome is believed to be approximately 1 out of every 100,000 births. For reasons unknown females are twice as likely to have Jacobsen Syndrome than males. No preference for any race or ethnicity has been reported so far.

Treatment with isotretinoin may induce substantial resolution of skin lesions, but the risk of secondary infection remains.

The incidence rate of ATR-16 syndrome is not easy to estimate and it is thought to be underdiagnosed. Scientists have described more than 20 cases as of 2013.

Individuals with Dup15q syndrome are at high risk for epilepsy, autism, and intellectual disability. Motor impairments are very common in individuals with the disorder. Rates of epilepsy in children with isodicentric duplications are higher than in children with interstitial duplications. A majority of patients with either duplication type (isodicentric or interstitial) have a history of gastrointestinal problems.

A study at the University of California, Los Angeles (UCLA) of 13 children with Dup15q syndrome and 13 children with nonsyndromic ASD (i.e., autism not caused by a known genetic disorder) found that, compared to children with nonsyndromic autism, children with Dup15q had significantly lower autism severity as measured by the Autism Diagnostic Observation Schedule (ADOS) (all children in the study met diagnostic criteria for ASD). However, children with Dup15q syndrome had significantly greater motor impairment and impairment of daily living skills than children in the nonsyndromic ASD group. Within the Dup15q syndrome cohort, children with epilepsy had greater cognitive impairment.

Dup15q syndrome is the common name for chromosome 15q11.2-q13.1 duplication syndrome. This is a neurodevelopmental disorder, caused by the partial duplication of Chromosome 15, that confers a strong risk for autism spectrum disorder, epilepsy, and intellectual disability. It is the most common genetic cause of autism, accounting for approximately 1-3% of cases. Dup15q syndrome includes both interstitial duplications and isodicentric duplications (i.e., Idic15) of 15q11.2-13.1.

Important genes likely involved in the etiology of Dup15q syndrome include "UBE3A", "GABRA5", "GABRB3", and "GABRG3". "UBE3A" is a ubiquitin-protein ligase that is involved in targeting proteins for degradation and plays an important role in synapse function. "GABRA5", "GABRB3", and "GABRG3" are gamma aminobutyric acid type A (GABA) receptor subunit genes and are likely important in Dup15q syndrome given the established role of GABA in the etiologies of autism and epilepsy.

PWS affects approximately 1 in 10,000 to 1 in 25,000 newborns. There are more than 400,000 people who live with PWS around the world.

Brain trauma in the developing human is a common cause (over 400,000 injuries per year in the US alone, without clear information as to how many produce developmental sequellae) of neurodevelopmental syndromes. It may be subdivided into two major categories, congenital injury (including injury resulting from otherwise uncomplicated premature birth) and injury occurring in infancy or childhood. Common causes of congenital injury are asphyxia (obstruction of the trachea), hypoxia (lack of oxygen to the brain) and the mechanical trauma of the birth process itself.

There is no specific treatment for micro syndrome, but there are ways to help the disorders, and illnesses that come with it. Many individuals with Micro Syndrome need permanent assistance from their disorders and inabilities to move and support themselves. Seizures are not uncommon and patients should get therapy to help control them, and many patients also require wheelchairs to move, so an assistant would be needed at all times.

Those with micro syndrome are born appearing normal. At the age of one, mental and physical delays become apparent, along with some limb spasms. By the age of eight micro syndrome has already set in, and the patient will have joint contractures, Ocular Atrophy will become noticeable, the patient will most likely lose ability to walk, speak, and sometimes move at all.

Nutrition disorders and nutritional deficits may cause neurodevelopmental disorders, such as spina bifida, and the rarely occurring anencephaly, both of which are neural tube defects with malformation and dysfunction of the nervous system and its supporting structures, leading to serious physical disability and emotional sequelae. The most common nutritional cause of neural tube defects is folic acid deficiency in the mother, a B vitamin usually found in fruits, vegetables, whole grains, and milk products. (Neural tube defects are also caused by medications and other environmental causes, many of which interfere with folate metabolism, thus they are considered to have multifactorial causes.) Another deficiency, iodine deficiency, produces a spectrum of neurodevelopmental disorders ranging from mild emotional disturbance to severe mental retardation. (see also cretinism)

Excesses in both maternal and infant diets may cause disorders as well, with foods or food supplements proving toxic in large amounts. For instance in 1973 K.L. Jones and D.W. Smith of the University of Washington Medical School in Seattle found a pattern of "craniofacial, limb, and cardiovascular defects associated with prenatal onset growth deficiency and developmental delay" in children of alcoholic mothers, now called fetal alcohol syndrome, It has significant symptom overlap with several other entirely unrelated neurodevelopmental disorders. It has been discovered that iron supplementation in baby formula can be linked to lowered I.Q. and other neurodevelopmental delays.

Jacobsen Syndrome is caused due to deletion of genetic material from the long arm of chromosome 11. The size of deletion may vary across patients but the deletion always occurs at the end terminal of the q arm of chromosome 11. There are three ways in which the deletion could occur:

de novo deletion- this is a random event that occurred during the formation of the sperm or the egg or during the cell division in the embryonic stage, where genes from chromosome 11 get deleted.

Imbalanced translocation- in this case a parent with balanced translocation or other types of chromosomal rearrangement can pass on these genes to their children which further results in an imbalanced translocation. In this case the affected children have deletions on chromosome 11 as well as some extra genetic material from another chromosome.

Ring chromosome 11- in this case genetic material from both long and short arm of the chromosome get deleted and the remaining part joins together and forms a ring like structure. Here the affected person would have symptoms associated with both 11q and 11p deletion.

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.

GMS syndrome is a syndrome characterised by goniodysgenesis, intellectual disability, and short stature.

Micro syndrome also known as WARBM, and Warburg–Sjo–Fledelius syndrome, is a rare autosomal recessive genetic disorder characterized by microcephaly, microcornea, congenital cataract, intellectual or developmental disability, optic atrophy, and hypogenitalism.

Though the outcome for individuals with either form of the tetrasomy is highly variable, mosaic individuals consistently experience a more favourable outcome than those with the non-mosaic form. Some affected infants die shortly after birth, particularly those with the non-mosaic tetrasomy. Many patients do not survive to reproductive age, while others are able to function relatively normally in a school or workplace setting. Early diagnosis and intervention has been shown to have a strong positive influence on the prognosis.

1p36 deletion syndrome (also known as monosomy 1p36) is a congenital genetic disorder characterized by moderate to severe intellectual disability, delayed growth, hypotonia, seizures, limited speech ability, malformations, hearing and vision impairment, and distinct facial features. The symptoms may vary, depending on the exact location of the chromosomal deletion.

The condition is caused by a genetic deletion (loss of a segment of DNA) on the outermost band on the short arm (p) of chromosome 1. It is one of the most common deletion syndromes. It is estimated that the syndrome occurs in one in every 5,000 to 10,000 births. Knowledge of the disorder has increased a great deal over the last decade, mainly because more patients have been accurately diagnosed and described in international medical literature.

Lujan–Fryns syndrome (LFS), also referred to as X-linked mental retardation with Marfanoid habitus and Lujan syndrome, is an X-linked genetic disorder that causes mild to moderate intellectual disability and features described as Marfanoid habitus, referring to a group of physical characteristics similar to those found in Marfan syndrome. These features include a tall, thin stature and long, slender limbs. LFS is also associated with psychopathology and behavioral abnormalities, and it exhibits a number of malformations affecting the brain and heart. The disorder is inherited in an X-linked dominant manner, and is attributed to a missense mutation in the "MED12" gene. There is currently no treatment or therapy for the underlying "MED12" malfunction, and the exact cause of the disorder remains unclear.

M2DS is one of the several types of X-linked intellectual disability. The cause of M2DS is a duplication of the MECP2 or Methyl CpG binding protein 2 gene located on the X chromosome (Xq28). The MeCP2 protein plays a pivotal role in regulating brain function. Increased levels of MECP2 protein results in abnormal neural function and impaired immune system. Mutations in the MECP2 gene are also commonly associated with Rett syndrome in females. Advances in genetic testing and more widespread use of Array Comparative Genomic Hybridization has led to increased diagnosis of MECP2 duplication syndrome. It is thought to represent ~1% of X-linked male mental disability cases.

The collecting system is the structure that collects urine directly from the kidney tissue and routes it by way of the ureter to the bladder. Structural renal abnormalities are rare in both sexes.

Zamzam–Sheriff–Phillips syndrome is a rare autosomal recessive congenital disorder. It is characterized by aniridia, ectopia lentis, abnormal upper incisors and intellectual disability. Not a lot of research has been undertaken of this particular disease so thus far there is no known gene that affects this condition. However it has been hypothesised that the symptoms described are found at a particular gene, though intellectual disability is believed to be due to a different genetic cause.

Consanguinuity (intermarrying among relatives such as cousins), often associated with autosomal recessive inheritance, has been attributed to the inheritance of this disease.

PWS is commonly associated with development of strabismus. In one study, over 50% of patients had strabismus, mainly esotropia.

Distal trisomy 10 is a rare chromosomal disorder that causes several physical defects and intellectual disability.

Humans, like all sexually reproducing species, have somatic cells that are in diploid [2N] state, meaning that N represent the number of chromosomes, and 2 the number of their copies. In humans, there are 23 chromosomes, but there are two sets of them, one from mother and one from father, totaling in 46, that are arranged according to their size, function and genes they carry. Each cell is supposed to have two of each, but sometimes due to mutations or malfunctions during cell division, mistakes are made that cause serious health problems. One such error is the cause of Distal trisomy 10q disorder.

Each chromosome has two arms, labeled p (for petite, or short) and q (for long). If both arms are equal in length, the chromosome is said to be metacentric. If arms' lengths are unequal, chromosome is said to be submetacentric, and if p arm is so short that is hard to observe, but still present, then the chromosome is acrocentric. In Distal Trisomy 10q disorder, end or distal portion of the q (long) arm of the chromosome number 10 appears to be present three times, rather than two times as it is supposed to be. This extra arm results in chromosome 10 trisomy, meaning that three arms are present. Depending on the length of the aberrant arm, the severity can vary from case to case. Often the source of this chromosomal error is a translocation in one of the parents. Sometimes it occurs spontaneously, in which case it is termed "de novo".

This syndrome has a large range of outcomes depending on how much chromosomal material is involved. Outcomes include: very slow postnatal growth, hypotonia, lack of coordination skills and mild to severe cases of intellectual disability, digestive issues, and heart and kidney problems. Individuals with this disorder can also be distinguished by their facial features. Number of support groups do exist in the United States, where affected families can meet and discuss problems they encounter, possible treatments and can find emotional support.

ATR-16 syndrome is caused by a deletion of part of chromosome 16, from p13.3 (a band on the short end of the chromosome) to the end of the chromosome. These can either be due to a balanced translocation or a de novo deletion. The genes affected include hemoglobin, alpha 1 (HBA1) and hemoglobin, alpha 2 (HBA2).