A 1998 review noted that life expectancy is usually normal, but that there have occasionally been reported neonatal deaths due to PCD. A 2016 longitudinal study followed 151 adults with PCD for a median of 7 years. Within that span, 7 persons died with a median age of 65.

Recent findings in genetic research have suggested that a large number of genetic disorders, both genetic syndromes and genetic diseases, that were not previously identified in the medical literature as related, may be, in fact, highly related in the genetypical root cause of the widely varying, phenotypically-observed disorders. Thus, Alstrom syndrome is a ciliopathy. Other known ciliopathies include primary ciliary dyskinesia, Bardet-Biedl syndrome, polycystic kidney and liver disease, nephronophthisis, Meckel-Gruber syndrome and some forms of retinal degeneration.

Research has revealed that a number of genetic disorders, not previously thought to be related, may indeed be related as to their root cause. Joubert syndrome is one such disease. It is a member of an emerging class of diseases called ciliopathies.

The underlying cause of the ciliopathies 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.

Currently recognized ciliopathies include Joubert syndrome, primary ciliary dyskinesia (also known as Kartagener Syndrome), Bardet-Biedl syndrome, polycystic kidney disease and polycystic liver disease, nephronophthisis, Alstrom syndrome, Meckel-Gruber syndrome and some forms of retinal degeneration.

Joubert syndrome type 2 is disproportionately frequent among people of Jewish descent.

A prognosis for Alström syndrome is complicated because it widely varies. Any person that has the syndrome have different set of disorders. Permanent blindness, deafness, and Type 2 diabetes may occur. Liver and kidney failure can progressively get worse. The life expectancy is usually reduced and the patients rarely live past 50 years old.

In a sample of 19 children, a 1997 study found that 3 died before the age of 3, and 2 never learned to walk. The children had various levels of delayed development with developmental quotients from 60 to 85.

A large British study from 2008 found a median estimated life expectancy of 11.6 years.

Bardet–Biedl syndrome (BBS) is a ciliopathic human genetic disorder that produces many effects and affects many body systems. It is characterized principally by obesity, retinitis pigmentosa, polydactyly, hypogonadism, and renal failure in some cases. Historically, slower mental processing has also been considered a principal symptom but is now not regarded as such.

One Finnish study which followed 25 cases from 18 families found that half the infants died within 3 days of birth and the other half died before 4 months of age.

While not precisely known, it is estimated that the general rate of incidence, according to Bergsma, for Meckel syndrome is 0.02 per 10,000 births. According to another study done six years later, the incidence rate could vary from 0.07 to 0.7 per 10,000 births.

This syndrome is a Finnish heritage disease. Its frequency is much higher in Finland, where the incidence is as high as 1.1 per 10,000 births. It is estimated that Meckel syndrome accounts for 5% of all neural tube defects there.

Bardet–Biedl syndrome is a pleiotropic disorder with variable expressivity and a wide range of clinical variability observed both within and between families. The main clinical features are rod–cone dystrophy, with childhood-onset visual loss preceded by night blindness; postaxial polydactyly; truncal obesity that manifests during infancy and remains problematic throughout adulthood; specific learning difficulties in some but not all individuals; male hypogenitalism and complex female genitourinary malformations; and renal dysfunction, a major cause of morbidity and mortality. There is a wide range of secondary features that are sometimes associated with BBS including

GRACILE syndrome is a very rare autosomal recessive genetic disorder, one of the Finnish heritage diseases. It is caused by mutation in BCS1L gene that occurs in at least 1 out of 47,000 live births in Finnish people.

GRACILE is an acronym for growth retardation, amino aciduria (amino acids in the urine), cholestasis, iron overload, lactic acidosis, and early death. Other names for this syndrome include Finnish lethal neonatal metabolic syndrome (FLNMS); lactic acidosis, Finnish, with hepatic hemosiderosis; and Fellman syndrome.

Hurler syndrome has an overall frequency of one per 100,000. The mucopolysaccharidoses as a whole have a frequency of one in every 25,000 births.

Meckel syndrome (also known as Meckel–Gruber Syndrome, Gruber Syndrome, Dysencephalia Splanchnocystica) is a rare, , ciliopathic, genetic disorder, characterized by renal cystic dysplasia, central nervous system malformations (occipital encephalocele), polydactyly (post axial), hepatic developmental defects, and pulmonary hypoplasia due to oligohydramnios.

Meckel–Gruber syndrome is named for Johann Meckel and Georg Gruber.

Recent findings in genetic research have suggested that a large number of genetic disorders, both genetic syndromes and genetic diseases, that were not previously identified in the medical literature as related, may be, in fact, highly related in the genetypical root cause of the widely varying, phenotypically-observed disorders. Such diseases are becoming known as ciliopathies. Known ciliopathies include primary ciliary dyskinesia, Bardet–Biedl syndrome, polycystic kidney and liver disease, nephronophthisis, Alström syndrome, Meckel–Gruber syndrome and some forms of retinal degeneration.

The cause of Senior–Løken syndrome type 5 has been identified to mutation in the NPHP1 gene which adversely affects the protein formation mechanism of the cilia.

Laurence–Moon syndrome (LMS) is a rare autosomal recessive genetic disorder associated with retinitis pigmentosa, spastic paraplegia, and mental disabilities.

The exact genetic defect in Galloway Mowat syndrome is yet to be discovered. However, mutations in podocyte proteins, such as nephrin, alpha-actinin 4, and podocin, are associated with proteinuria and nephrotic syndrome. There is reduced expression of synaptopodin, GLEPP1, and nephrin in Galloway-Mowat syndrome, but these are likely secondary to the proteinuria, likely not the proteins mutated in Galloway-Mowat syndrome.

The biochemical lesion appears to be in the Kinase, Endopeptidase and Other Proteins of small Size (KEOPS)/Endopeptidase-like and Kinase associated to transcribed Chromatin (EKC) (KEOPS/EKC) complex. Sequencing of genes in 37 cases of this condition revealed muations in the OSGEP, TP53RK, TPRKB and LAGE3 genes all of which encode subunits in the KEOPS complex. Members of this complex are found in bacteria, archaea and eukaryotes and are highly conserved. The function of this complex is still under investigation.

Galloway Mowat syndrome is an autosomal recessive disorder, which 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.

Epidemiologically speaking, nephronophthisis, occurs equally in both sexes, and has an estimate 9 in about 8 million rate in individuals. Nephronophthisis is the leading monogenic cause of end-stage renal disease.

LMS 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.

A ciliopathy is a genetic disorder of the cellular cilia or the cilia anchoring structures, the basal bodies, or of ciliary function.

Although ciliopathies are usually considered to involve proteins that localize to motile and/or immotile (primary) cilia or centrosomes, it is possible for ciliopathies to be associated with proteins such as XPNPEP3, which localizes to mitochondria but is believed to affect ciliary function through proteolytic cleavage of ciliary proteins.

Significant advances in understanding the importance of cilia were made beginning in the mid-1990s. However, the physiological role that this organelle plays in most tissues remains elusive. Additional studies of how ciliary dysfunction can lead to such severe disease and developmental pathologies is a subject of current research.

The side effects and seriousness of Bardet-Biedl disorder fluctuates significantly even among people inside their family. affected people won't have the greater part of the indications talked about underneath. Moreover, the seriousness of particular indications may shift enormously also. The effects of this disorder include cone-rod dystrophy, postaxial polydactyly, truncal obesity, kidney abnormalities and learning difficulties.

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.

When accompanied by the combination of situs inversus (reversal of the internal organs), chronic sinusitis, and bronchiectasis, it is known as Kartagener syndrome (only 50% of primary ciliary dyskinesia cases include situs inversus).

Wolf–Hirschhorn syndrome is a microdeletion syndrome caused by a deletion within HSA band 4p16.3 of the short arm of chromosome 4, particularly in the region of and . About 87% of cases represent a "de novo" deletion, while about 13% are inherited from a parent with a chromosome translocation. In the cases of familial translocation, there is a 2 to 1 excess of maternal transmission. Of the "de novo" cases, 80% are paternally derived. Severity of symptoms and expressed phenotype differ based on the amount of genetic material deleted. The critical region for determining the phenotype is at 4p16.3 and can often be detected through genetic testing and fluorescence in situ hybridization (FISH). Genetic testing and genetic counseling is offered to affected families.