The diagnosis of PPS has been made in several ethnic groups, including Caucasian, Japanese, and sub-Saharan African. Males and females are equally likely to suffer from the syndrome. Since the disorder is very rare, its incidence rate is difficult to estimate, but is less than 1 in 10,000.

The prognosis is poor; affected individuals are either stillborn or die shortly after birth. The longest survival reported in literature is of 134 days.

This syndrome is transmitted as an autosomal recessive disorder and there is a risk for recurrence of 25% in future pregnancies.

There have been 30 cases of Marden-Walker Syndrome reported since 1966. The first case of this was in 1966 a female infant was diagnosed with blepharophimosis, joint contractures, arachnodactyly and growth development delay. She ended up passing at 3 months due to pneumonia.

The reported incidence of constriction ring syndrome varies from 1/1200 and 1/15000 live births. The prevalence is equally in male and female.

Fetomaternal factors like prematurity, maternal illnes, low birth weight and maternal drug exposure are predisposing factors for the constriction ring syndrome.

No positive relationship between CRS and genetic inheritance has been reported.

Van der Woude syndrome (VDWS) and popliteal pterygium syndrome (PPS) are allelic variants of the same condition; that is, they are caused by different mutations of the same gene. PPS includes all the features of VDWS, plus popliteal pterygium, syngnathia, distinct toe/nail abnormality, syndactyly, and genito-urinary malformations.

This disorder is caused by an abnormality of the TBCE gene, the locus for which is on Chromosome 1q42.3. The locus is a 230 kb region of gene with identified deletions and mutations in affected individuals. There are rare cases of the disorder not being due to a TBCE gene abnormality.

In a newborn boy thought to have Fryns syndrome, Clark and Fenner-Gonzales (1989) found mosaicism for a tandem duplication of 1q24-q31.2. They suggested that the gene for this disorder is located in that region. However, de Jong et al. (1989), Krassikoff and Sekhon (1990), and Dean et al. (1991) found possible Fryns syndrome associated with anomalies of chromosome 15, chromosome 6, chromosome 8(human)and chromosome 22, respectively. Thus, these cases may all represent mimics of the mendelian syndrome and have no significance as to the location of the gene for the recessive disorder.

By array CGH, Slavotinek et al. (2005) screened patients with DIH and additional phenotypic anomalies consistent with Fryns syndrome for cryptic chromosomal aberrations. They identified submicroscopic chromosome deletions in 3 probands who had previously been diagnosed with Fryns syndrome and had normal karyotyping with G-banded chromosome analysis. Two female infants were found to have microdeletions involving 15q26.2 (see 142340), and 1 male infant had a deletion in band 8p23.1 (see 222400).

Genitopatellar Syndrome is an autosomal dominant inheritance where the mutation in the KAT6B causes the syndrome. The KAT6B gene is responsible for making an enzyme called histone acetyltransferase which functions in regulating and making of histone which are proteins that attach to DNA and give the chromosomes their shape. The function of histone acetyltransferase produced from KAT6B is unknown but it is considered as a regulator of early developments. There is little known about how the mutation in the KAT6B causes the syndrome but researchers suspects that the mutations occur near the end of the KAT6B gene and causes it to produce shortened acetyltransferase enzyme. The shortened enzyme alters the regulation of other genes. On the other hand, the mutation of KAT6B leading to the specific features of genitopatellar syndrome is still not surely proven.

A low socioeconomic status in a deprived neighborhood may include exposure to “environmental stressors and risk factors.” Socioeconomic inequalities are commonly measured by the Cartairs-Morris score, Index of Multiple Deprivation, Townsend deprivation index, and the Jarman score. The Jarman score, for example, considers “unemployment, overcrowding, single parents, under-fives, elderly living alone, ethnicity, low social class and residential mobility.” In Vos’ meta-analysis these indices are used to view the effect of low SES neighborhoods on maternal health. In the meta-analysis, data from individual studies were collected from 1985 up until 2008. Vos concludes that a correlation exists between prenatal adversities and deprived neighborhoods. Other studies have shown that low SES is closely associated with the development of the fetus in utero and growth retardation. Studies also suggest that children born in low SES families are “likely to be born prematurely, at low birth weight, or with asphyxia, a birth defect, a disability, fetal alcohol syndrome, or AIDS.” Bradley and Corwyn also suggest that congenital disorders arise from the mother’s lack of nutrition, a poor lifestyle, maternal substance abuse and “living in a neighborhood that contains hazards affecting fetal development (toxic waste dumps).” In a meta-analysis that viewed how inequalities influenced maternal health, it was suggested that deprived neighborhoods often promoted behaviors such as smoking, drug and alcohol use. After controlling for socioeconomic factors and ethnicity, several individual studies demonstrated an association with outcomes such as perinatal mortality and preterm birth.

Cenani–Lenz syndactylism is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.

In a test of the theory that the locus associated with the disorder was at 15q13-q14, FMN1 and GREM1 were eliminated as candidates.

It is associated with "LRP4".

Cenani–Lenz syndactylism, also known as Cenani–Lenz syndrome or Cenani–syndactylism, is an autosomal recessive congenital malformation syndrome involving both upper and lower extremities.

Halal syndrome is a rare disorder characterised by microcephaly, cleft palate, and variable other anomalies.

The effects of paternal age on offspring are not yet well understood and are studied far less extensively than the effects of maternal age. Fathers contribute proportionally more DNA mutations to their offspring via their germ cells than the mother, with the paternal age governing how many mutations are passed on. This is because, as humans age, male germ cells acquire mutations at a much faster rate than female germ cells.

Around a 5% increase in the incidence of ventricular septal defects, atrial septal defects, and patent ductus arteriosus in offspring has been found to be correlated with advanced paternal age. Advanced paternal age has also been linked to increased risk of achondroplasia and Apert syndrome. Offspring born to fathers under the age of 20 show increased risk of being affected by patent ductus arteriosus, ventricular septal defects, and the tetralogy of Fallot. It is hypothesized that this may be due to environmental exposures or lifestyle choices.

Research has found that there is a correlation between advanced paternal age and risk of birth defects such as limb anomalies, syndromes involving multiple systems, and Down's syndrome. Recent studies have concluded that 5-9% of Down's syndrome cases are due to paternal effects, but these findings are controversial.

There is concrete evidence that advanced paternal age is associated with the increased likelihood that a mother will suffer from a miscarriage or that fetal death will occur.

Until recently, the medical literature did not indicate a connection among many genetic disorders, both genetic syndromes and genetic diseases, that are now being found to be related. As a result of new genetic research, some of these are, in fact, highly related in their root cause despite the widely varying set of medical symptoms that are clinically visible in the disorders. Ellis–van Creveld syndrome is one such disease, part of an emerging class of diseases called ciliopathies. The underlying cause may be a dysfunctional molecular mechanism in the primary cilia structures of the cell, organelles which are present in many cellular types throughout the human body. The cilia defects adversely affect "numerous critical developmental signaling pathways" essential to cellular development and thus offer a plausible hypothesis for the often multi-symptom nature of a large set of syndromes and diseases. Known ciliopathies include primary ciliary dyskinesia, Bardet–Biedl syndrome, polycystic kidney and liver disease, nephronophthisis, Alstrom syndrome, Meckel–Gruber syndrome and some forms of retinal degeneration.

Weyers acrofacial dysostosis is due to another mutation in the EVC gene and hence is allelic with Ellis–van Creveld syndrome.

Ellis–van Creveld syndrome often is the result of founder effects in isolated human populations, such as the Amish and some small island inhabitants. Although relatively rare, this disorder does occur with higher incidence within founder-effect populations due to lack of genetic variability. Observation of the inheritance pattern has illustrated that the disease is autosomal recessive, meaning that both parents have to carry the gene in order for an individual to be affected by the disorder.

Ellis–van Creveld syndrome is caused by a mutation in the "EVC" gene, as well as by a mutation in a nonhomologous gene, "EVC2", located close to the EVC gene in a head-to-head configuration. The gene was identified by positional cloning. The EVC gene maps to the chromosome 4 short arm (4p16). The function of a healthy EVC gene is not well understood at this time.

Feingold syndrome is caused by mutations in the neuroblastoma-derived V-myc avian myelocytomatosis viral-related oncogene (MYCN) which is located on the short arm of chromosome 2 (2p24.1).

Current research is focusing on clearly defining the phenotype associated with tetrasomy 18p and identifying which genes cause medical and developmental problems when present in four copies.

Feingold syndrome (also called oculodigitoesophagoduodenal syndrome) is a rare autosomal dominant hereditary disorder. It is named after Murray Feingold, an American physician who first described the syndrome in 1975. Until 2003, at least 79 patients have been reported worldwide.

Genitopatellar syndrome is a rare disorder with characteristic craniofacial features, congenital flexion contractures of the lower limbs, absent or abnormal patellae, urogenital anomalies, and severe psychomotor retardation.

In 2012, it was shown that mutations in the gene KAT6B cause the syndrome.

Neu–Laxova syndrome (also known as Neu syndrome or Neu-Povysilová syndrome, abbreviated as NLS) is a rare autosomal recessive disorder characterized by severe intrauterine growth restriction and multiple congenital malformations. Neu–Laxova syndrome is a very severe disorder, leading to stillbirth or neonatal death. It was first described by Dr. Richard Neu in 1971 and Dr. Renata Laxova in 1972 as a lethal disorder in siblings with multiple malformations. Neu–Laxova syndrome is an extremely rare disorder with less than 100 cases reported in medical literature.

Marden–Walker syndrome (MWS) is a rare autosomal recessive congenital disorder. It is characterized by blepharophimosis, microcephaly, micrognathia, multiple joint contractures, arachnodactyly, camptodactyly, kyphoscoliosis, and delayed motor development and is often associated with cystic dysplastic kidneys, dextrocardia, Dandy-Walker malformation, and agenesis of corpus callosum".

The cause of Poland syndrome is unknown. However, an interruption of the embryonic blood supply to the arteries that lie under the collarbone (subclavian arteries) at about the 46th day of embryonic development is the prevailing theory.

The subclavian arteries normally supply blood to embryonic tissues that give rise to the chest wall and hand. Variations in the site and extent of the disruption may explain the range of signs and symptoms that occur in Poland syndrome. Abnormality of an embryonic structure called the apical ectodermal ridge, which helps direct early limb development, may also be involved in this disorder.

Edwards syndrome occurs in about one in 5,000 live births, but more conceptions are affected by the syndrome because the majority of those diagnosed with the condition prenatally will not survive to birth. Although women in their 20s and early 30s may conceive babies with Edwards syndrome, the risk of conceiving a child with it increases with a woman's age. The average maternal age for conceiving a child with this disorder is 32½.

Oral-facial-digital syndrome is a group of at least 13 related conditions that affect the development of the mouth, facial features, and digits in between 1 in 50,000 to 250,000 newborns with the majority of cases being type I (Papillon-League-Psaume syndrome).

The syndromes associated with central polydactyly are:

Bardet–Biedl syndrome,

Meckel syndrome,

Pallister–Hall syndrome,

Legius syndrome,

Holt–Oram syndrome,

Also, central polydactyly can be associated with syndactyly and cleft hand.

Other syndromes including polydactyly include acrocallosal syndrome, basal cell nevus syndrome, Biemond syndrome, ectrodactyly-ectodermal dysplasias-cleft lip/palate syndrome, mirror hand deformity, Mohr syndrome, oral-facial-digital syndrome, Rubinstein-Taybi syndrome, short rib polydactyly, and VATER association.

It can also occur with a triphalangeal thumb.