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

Symptoms for Alström syndrome generally appear during infancy with great variability in age. Some of the symptoms include:

- Heart failure (Dilated cardiomyopathy) in over 60% of cases, usually within the first few weeks after birth, but sometimes the onset is in adolescence or adulthood.

- Light sensitivity and vision problems (Cone-rod dystrophy) in all cases, usually within 15 months of birth and progressively worsening until about 20 years of age

- Delays in early, developmental milestones in 50% of cases, learning disabilities in about 30% of cases

- Obesity in 100% of cases, apparent by 5 years of age, but often apparent in infancy (Alström infants usually have normal birth weights, and by adolescence, weights tend to be in the high-normal to normal range)

- Nystagmus (usually affects the children) one of the first symptoms to occur which causes involuntary rapid eye movement.

- Heart failure (Dilated cardiomyopathy) in over 60% of cases, usually within the first few weeks after birth, but sometimes the onset is in adolescence or adulthood.(chronic)

- Mild to moderate bilateral sensorineural hearing loss.

- Type 2 diabetes usually occurs in early childhood.

- Hyperinsulinemia/ insulin resistance—development of high level of insulin in blood.

- Steatosis (fatty liver) and elevated transaminases (liver enzymes) often develop in childhood and can progress in some patients to cirrhosis and liver failure.

- Endocrine dysfunctions may occur where the patient may experience an under or over active thyroid gland, weak growth hormone, increased androgen in females, and low testosterone in males.

- Slowly progressive kidney failure can occur in the second to fourth decade of life.

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.

Most of the signs and symptoms of the Joubert syndrome appear very early in infancy with most children showing delays in gross motor milestones. Although other signs and symptoms vary widely from individual to individual, they generally fall under the hallmark of cerebellum involvement or in this case, lack thereof. Consequently, the most common features include ataxia (lack of muscle control), hyperpnea (abnormal breathing patterns), sleep apnea, abnormal eye and tongue movements, and hypotonia in early childhood. Other malformations such as polydactyly (extra fingers and toes), cleft lip or palate, tongue abnormalities, and seizures may also occur. Developmental delays, including cognitive, are always present to some degree.

Those suffering from this syndrome often exhibit specific facial features such as a broad forehead, arched eyebrows, ptosis (droopy eyelids), hypertelorism (widely spaced eyes), low-set ears and a triangle shaped mouth. Additionally, this disease can include a broad range of other abnormalities to other organ systems such as retinal dystrophy, kidney diseases, liver diseases, skeletal deformities and endocrine (hormonal) problems.

All types of Griscelli syndrome have distinctive skin and hair coloring.

Type 1 is associated with eurological abnormalities. These include delayed development, intellectual disability, seizures, hypotonia and eye abnormalities.

Type 2 - unlike type 1 - is not associated primary neurological disease but is associated with an uncontrolled T lymphocyte expansion and macrophage activation syndrome. It is often associated with the hemophagocytic syndrome. This latter condition may be fatal in the absence of bone marrow transplantation.

Persons with type 3 have the typical light skin and hair coloring but are otherwise normal.

Alström syndrome, also called Alstrom-Halgren syndrome, is a rare genetic disorder caused by mutations in the gene ALMS1. It is among the rarest genetic disorders in the world, as currently it has only 266 reported cases in medical literature and over 501 known cases in 47 countries. It was first described by Carl-Henry Alström in Sweden in 1959. Alstrom syndrome is sometimes confused with Bardet-Biedl syndrome, which has similar symptoms. Bardet-Biedl syndrome tends to have later onset in its symptoms. The likelihood of two carrier parents both passing the gene and therefore having a child affected by the syndrome is 25% with each pregnancy. The likelihood of having a child who is only a carrier of the gene is 50% with each pregnancy. The likelihood of a child receiving normal genes from both parents and being considered to be "genetically" normal is 25%. The risk for carrying the gene is equivalent for both males and females.

"Alström syndrome (AS) is a rare autosomal recessive disease characterized by multiorgan dysfunction. The key features are childhood obesity, blindness due to congenital retinal dystrophy, and sensorineural hearing loss. Associated endocrinologic features include hyperinsulinemia, early-onset type 2 diabetes, and hypertriglyceridemia."

Thus, AS shares several features with the common metabolic syndrome, namely obesity, hyperinsulinemia, and hypertriglyceridemia. Mutations in the ALMS1 gene have been found to be causative for AS with a total of 79 disease-causing mutations having been described." Prevalence estimates have ranged from 1 in 10,000 to fewer than 1 in 1,000,000 individuals in the general population.

A wide variety of symptoms are potential clinical features of ciliopathy.

- Chemosensation abnormalities, typically via ciliated epithelial cellular dysfunction.

- Defective thermosensation or mechanosensation, often via ciliated epithelial cellular dysfunction.

- Cellular motility dysfunction

- Issues with displacement of extracellular fluid

- Paracrine signal transduction abnormalities

In organisms of normal health, cilia are critical for:

- development

- homeostasis

- reproduction

For individuals with MORM syndrome, symptoms do not appear until about one year into the child’s life span. From conception to birth, individuals with MORM syndrome appear asymptotic with no abnormal characteristics. Vision is negatively affected within the first year of life, particularly night vision. Individuals with MORM syndrome experience decreased visual acuity meaning their ability to see distinct sharp lines decreases. Vision quality continues to deteriorate until age three. Any further reduction in vision acuity is not observed until the individual is between the ages thirty to forty. Delayed sentence processing and intellectual disability is associated with individuals with MORM syndrome, primarily observed at age four. Individuals continue to develop and grow until they are five to twelve years old. During this age bracket, truncal obesity can develop. Truncal obesity is a term used to describe the build up of fat around ones trunk or torso as opposed to the persons extremities. Males enter puberty at around age twelve and develop normally except for their sex organ. The males penis will remain at the prepubescent size resulting in a micropenis. The life span of individuals with MORM syndrome is unclear as well as the fertility of these individuals.

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

Senior–Løken syndrome is a congenital eye disorder, first characterized in 1961. It is a rare, ciliopathic, autosomal recessive disorder characterized by nephronophthisis and progressive eye disease.

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.

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.

Joubert syndrome is a rare autosomal recessive genetic disorder that affects the cerebellum, an area of the brain that controls balance and coordination.

Joubert syndrome is one of the many genetic syndromes associated with syndromic retinitis pigmentosa. The syndrome was first identified in 1969 by pediatric neurologist Marie Joubert in Montreal, Quebec, Canada, while working at the Montreal Neurological Institute and McGill University.

Clinically, McKusick–Kaufman syndrome is characterized by a combination of three features: postaxial polydactyly, heart defects, and genital abnormalities:

- Vaginal atresia with hydrometrocolpos

- Double vagina and/or uterus.

- Hypospadias, chordee (a downward-curving penis), and undescended testes (cryptorchidism).

- ureter stenosis or ureteric atresia

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.

Griscelli syndrome type 2 (also known as "partial albinism with immunodeficiency") is a rare autosomal recessive syndrome characterized by variable pigmentary dilution, hair with silvery metallic sheen, frequent pyogenic infections, neutropenia, and thrombocytopenia.

It involves numerous anomalies including:

- Post-axial polydactyly

- Congenital heart defects (most commonly an atrial septal defect producing a common atrium, occurring in 60% of affected individuals)

- Teeth present at birth (natal teeth)

- Fingernail dysplasia

- Short-limbed dwarfism, mesomelic pattern

- Short ribs

- Cleft palate

- Malformation of the wrist bones (fusion of the hamate and capitate bones).

Ellis–van Creveld Syndrome (also called "chondroectodermal dysplasia" or "mesoectodermal dysplasia" but see 'Nomenclature' section below) is a rare genetic disorder of the skeletal dysplasia type.

The main consequence of impaired ciliary function is reduced or absent mucus clearance from the lungs, and susceptibility to chronic recurrent respiratory infections, including sinusitis, bronchitis, pneumonia, and otitis media. Progressive damage to the respiratory system is common, including progressive bronchiectasis beginning in early childhood, and sinus disease (sometimes becoming severe in adults). However, diagnosis is often missed early in life despite the characteristic signs and symptoms. In males, immotility of sperm can lead to infertility, although conception remains possible through the use of in vitro fertilization and, as well as this, there have been reported cases where sperm were able to move. Trials have also shown that there is a marked reduction in fertility in female sufferers of Kartagener's Syndrome due to dysfunction of the oviductal cilia.

Many affected individuals experience hearing loss and show symptoms of otitis media which demonstrate variable responsiveness to the insertion of myringotomy tubes or grommets. Some patients have a poor sense of smell, which is believed to accompany high mucus production in the sinuses (although others report normal - or even acute - sensitivity to smell and taste). Clinical progression of the disease is variable, with lung transplantation required in severe cases. Susceptibility to infections can be drastically reduced by an early diagnosis. Treatment with various chest physiotherapy techniques has been observed to reduce the incidence of lung infection and to slow the progression of bronchiectasis dramatically. Aggressive treatment of sinus disease beginning at an early age is believed to slow long-term sinus damage (although this has not yet been adequately documented). Aggressive measures to enhance clearance of mucus, prevent respiratory infections, and treat bacterial superinfections have been observed to slow lung-disease progression. Although the true incidence of the disease is unknown, it is estimated to be 1 in 32,000,

although the actual incidence may be as high as 1 in 15,000.

This syndrome is similar to Bardet–Biedl syndrome (BBS). http://omim.org/entry/210350

The 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 kidney failure in some cases. Historically, mental retardation has been considered a principal symptom but is now not regarded as such.

Individuals with 3-M syndrome suffer from severe prenatal growth retardation due to growth delays during fetal development resulting in a low birth weight. Growth delays continue after birth throughout childhood and adolescence, ultimately leading to a short stature.

Many of the physical features associated with the disorder are congenital. Characteristic craniofacial abnormalities typically include a long, narrow head that is disproportionate to the body size, a broad and prominent forehead, and a triangular-shaped face with a hypoplastic midface, pointed chin, prominent mouth, fleshy tipped upturned nose, large ears, and full lips. The teeth may be abnormally crowded together in some affected individuals.

McKusick–Kaufman syndrome is a genetic condition associated with MKKS.

The condition is named for Dr. Robert L. Kaufman and Victor McKusick. It is sometimes known by the abbreviation MKS. In infancy it can be difficult to distinguish between MKS and the related Bardet–Biedl syndrome, as the more severe symptoms of the latter condition rarely materialise before adulthood.

Acrocallosal syndrome (also known as ACLS) is a rare autosomal recessive syndrome characterized by corpus callosum agenesis, polydactyly, multiple dysmorphic features, motor and mental retardation, and other symptoms. The syndrome was first described by Albert Schinzel in 1979.

It is associated with "GLI3".

MORM syndrome is an autosomal recessive congenital disorder This means that the disorder is present from birth and is likely the result of both healthy parents passing on a defective gene, associated with MORM syndrome, to their offspring. The disorder is not dependent on sex of the offspring, both male and female offspring are equally likely to inherit the disorder. The term MORM is used to describe the characteristics associated with the disorder which include mental retardation, truncal obesity, retinal dystrophy, and micropenis". The disorder shares similar characteristics with Bardet-Biedl syndrome and Cohen syndrome, both of which are autosomal recessive genetic disorders. MORM syndrome can be distinguished from the above disorders because symptoms appear at a young age.

The syndrome is caused by a mutation in the INPP5E gene which can be located on chromosome 9 in humans. Further mapping resulted in the identification of a MORM syndrome locus on chromosome 9q34.3 between the genetic markers D9S158 and D9S905.