Symptoms include:

- intellectual disability (more than half of the patients have an IQ below 50)

- microcephaly

- sometimes pancytopenia (low blood counts)

- cryptorchidism

- low birth weight

- dislocations of pelvis and elbow

- unusually large eyes

- low ears

- small chin

Fingernails and toenails may be thick, abnormally shaped, discolored, ridged, slow-growing, or brittle. The cuticles may be prone to infections.

Individuals affected by an ED syndrome frequently have abnormalities of the hair follicles. Scalp and body hair may be thin, sparse, and very light in color, even though beard growth in affected males may be normal. The hair may grow very slowly or sporadically and it may be excessively fragile, curly, or even twisted.

Meleda disease (MDM) or "mal de Meleda", also called Mljet disease, keratosis palmoplantaris and transgradiens of Siemens, (also known as "Acral keratoderma," "Mutilating palmoplantar keratoderma of the Gamborg-Nielsen type," "Palmoplantar ectodermal dysplasia type VIII", and "Palmoplantar keratoderma of the Norrbotten type") is an extremely rare autosomal recessive congenital skin disorder in which dry, thick patches of skin develop on the soles of the hands and feet, a condition known as palmoplantar hyperkeratosis.

The clinical presentation of HFM is quite variable. The severity may depend on the extent of the area with an insufficient blood supply "in utero", and the gestational age of the fetus at which this occurs. In some people, the only physical manifestation may be a small and underdeveloped external ear. In more severe cases, multiple parts of the face may be affected. Some people with HFM may have sensorineural hearing loss and decreased visual acuity or even blindness.

Goldenhar syndrome can be thought of as a particularly severe form of HFM, in which extracranial anomalies are present to some extent. Some of the internal organs (especially the heart, kidneys, and lungs) may be underdeveloped, or in some cases even absent altogether. The affected organs are typically on the same side as the affected facial features, but bilateral involvement occurs in approximately 10% of cases. Deformities of the vertebral column such as scoliosis may also be observed in Goldenhar syndrome.

While there is no universally accepted grading scale, the OMENS scale (standing for Orbital, Mandible, Ear, Nerves and Soft tissue) was developed to help describe the heterogeneous phenotype that makes up this sequence or syndrome.

Intellectual disability is not typically seen in people with HFM.

Naxos disease (also known as "Diffuse non-epidermolytic palmoplantar keratoderma with woolly hair and cardiomyopathy," "Diffuse palmoplantar keratoderma with woolly hair and arrhythmogenic right ventricular cardiomyopathy firstly described in Naxos island by Dr Nikos Protonotarios," and "Naxos disease") is a cutaneous condition characterized by a palmoplantar keratoderma. The prevalence of the syndrome is about 1 person in 1000 in the Hellenic islands.

It has been associated with mutations in the genes encoding desmoplakin and plakoglobin.

Haim–Munk syndrome (also known as "palmoplantar keratoderma with periodontitis and arachnodactyly and acro-osteolysis") is a cutaneous condition caused by a mutation in the cathepsin C gene. It was named after Dr. Salim Haim and Dr. Munk.

Corneodermatosseous syndrome (also known as "CDO syndrome") is an autosomal dominant condition with onset in infancy, characterized by corneal dystrophy, photophobia, diffuse palmoplantar keratoderma, distal onycholysis, skeletal abnormalities, with brachydactyly, short stature, and medullary narrowing of digits.

The following is a list of symptoms that have been associated with Roberts syndrome:

- Bilateral Symmetric Tetraphocomelia- a birth defect in which the hands and feet are attached to shortened arms and legs

- Prenatal Growth Retardation

- Hypomelia (Hypoplasia)- the incomplete development of a tissue or organ; less drastic than aplasia, which is no development at all

- Oligodactyly- fewer than normal number of fingers or toes

- Thumb Aplasia- the absence of a thumb

- Syndactyly- condition in which two or more fingers (or toes) are joined together; the joining can involve the bones or just the skin between the fingers

- Clinodactyly- curving of the fifth finger (little finger) towards the fourth finger (ring finger) due to the underdevelopment of the middle bone in the fifth finger

- Elbow/Knee Flexion Contractures- an inability to fully straighten the arm or leg

- Cleft Lip- the presence of one or two vertical fissures in the upper lip; can be on one side (unilateral) or on both sides (bilateral)

- Cleft Palate- opening in the roof of the mouth

- Premaxillary Protrusion- upper part of the mouth sticks out farther than the lower part of the mouth

- Micrognathia- small chin

- Microbrachycephaly- smaller than normal head size

- Malar Hypoplasia- underdevelopment of the cheek bones

- Downslanting Palpebral Fissures- the outer corners of the eyes point downwards

- Ocular Hypertelorism- unusually wide-set eyes

- Exophthalmos- a protruding eyeball

- Corneal Clouding- clouding of the front-most part of the eye

- Hypoplastic Nasal Alae- narrowing of the nostrils that can decrease the width of the nasal base

- Beaked Nose- a nose with a prominent bridge that gives it the appearance of being curved

- Ear Malformations

- Intellectual disability

- Encephalocele (only in severe cases)- rare defect of the neural tube characterized by sac-like protrusions of the brain

Mortality is high among those severely affected by Roberts syndrome; however, mildly affected individuals may survive to adulthood

Dental features:

- small teeth in males

- pointed (screwdriver shaped or conical) incisors (sometimes called Hutchinson teeth)

- incisors with an irregulal incisal edge

- canines: enlarged and globular; may be dome or bud shaped with trilobed edge

- premolars and molars: small, round and globular; may have supernumary lobes (mulberry or lotus flower shape)

- widely separated teeth (diastemma)

- hypoplastic enamel

- dental agenesis

- presence of mesiodents (median incisor behind normal upper incisors)

- pulp chamber anomalies

Facial features:

- anteverted pinnae

- long face

- prominent nasal bridge and nose

- prognathism occasionally

Ophthalmic features:

- bilateral congenital nuclear opacities (100%)

- severe amblyopia

- nystagmus (93%)

- strabismus (43%)

- microcornea (96%)

- congenital glaucoma

- scleral staphylomas

- retinal cystoid degeneration

- microphthalmia

These lead to severe visual impairment in affected males.

Other:

- The fourth metacarpal may be shortened

30% of patients also have some degree of intellectual impairment: of these 80% are mildly to moderately affected: the other 20% may have developmental delays and behavior problems.

Carrier females display milder variable symptoms of disease. Ocular signs are present in 90% of heterozygous females. These are typically lens opacities often involving the posterior Y sutures. More rarely dental anomalies and the characteristic facial features may also occur.

Hidrotic ectodermal dysplasia 2, or Clouston syndrome (referred to as HED2 throughout this entry) is characterized by partial or total alopecia, dystrophy of the nails, hyperpigmentation of the skin (especially over the joints), and clubbing of the fingers. Sparse scalp hair and dysplastic nails are seen early in life. In infancy, scalp hair is wiry, brittle, patchy, and pale; progressive hair loss may lead to total alopecia by puberty. The nails may be milky white in early childhood; they gradually become dystrophic, thick, and distally separated from the nail bed. Palmoplantar keratoderma may develop during childhood and increases in severity with age. The clinical manifestations are highly variable even within the same family.

Lelis syndrome it is a genetic disorder, a rare condition with dermatological and dental findings characterized by the association of ectodermal dysplasia (hypotrichosis and hypohidrosis) with acanthosis nigricans. Other clinical features may include palmoplantar hyperkeratosis, nail dystrophy, intellectual deficit, disturbances of skin pigmentation (perioral and periorbital hyperpigmentation, vitiligo, and perinevic leukoderma) and hypodontia. Transmission is autosomal recessive.

Bart–Pumphrey syndrome (also known as "Palmoplantar keratoderma with knuckle pads and leukonychia and deafness") is a cutaneous condition characterized by hyperkeratoses (knuckle pads) over the metacarpophalangeal, proximal and distal interphalangeal joints.

It was characterized in 1967.

It can be associated with GJB2.

The following signs are associated with the disease

- Abnormal heart development

- Abnormal skeletal development

- Hypermobile joints

- Large fingers

- Knock-knees

- Widely spaced teeth

- Bell-shaped chest (flared ribs)

- Compression of spinal cord

- Enlarged heart

- Dwarfism

- Heart murmur

- below average height for certain age

Patients with Morquio syndrome appear healthy at birth. They often present with spinal deformity, and there is growth retardation and possibly genu valgum in the second or third year of life. A patient with Morquio's syndrome is likely to die at an early age. Symptoms of the disease may include:

- Short stature and short neck (caused by flat vertebrae)

- Moderate kyphosis or scoliosis

- Mild pectus carinatum ("pigeon chest")

- Cervical spine: odontoid hypoplasia, atlanto-axial instability; may be associated with myelopathy with gradual loss of walking ability

- Joint laxity, mild dysostosis multiplex, dysplastic hips, large unstable knees, large elbows and wrists, and flat feet

- The combined abnormalities usually result in a duck-waddling gait

- Mid-face hypoplasia and mandibular protrusion

- Thin tooth enamel

- Corneal clouding

- Mild hepatosplenomegaly

Regarding the life span of people with Morquio, some can die as early as 2 or 3 years old, and some can live up to 60 or 70 years old. The oldest known person with Morquio syndrome type IV A was Kenneth D. Martin, who was born in Osage City, Kansas, USA and was 81 years old at the time of his death

The only symptoms seen consistently in all 24 diagnosed cases are epilepsy, amelogenesis imperfecta in both primary and secondary teeth, and developmental delay. All symptoms experienced are experienced in varying degrees across each case.

There are some physical symptoms that have been associated with KTS. The most prominent symptom is amelogenesis imperfecta which gives the teeth a stained brown-yellow color. The enamel is thin, rough, and prone to crumbling. Two types of amelogenesis imperfecta (AI) have been seen in KTS patients. The first is Hypoplastic which is caused by the enamel being underdeveloped, and the second is hypo-calcified which causes the enamel to be soft and chalky. AI originated as a heterogeneous syndrome but has been observed as homogeneous in the case of KTS. Other physical symptoms that some cases have presented with include broad thumbs and toes, microcephaly, coarse hair, mildly asymmetric skull, up slanting palpebral fissures which is where the outside corners of the eyes are higher than normal, and smooth philtrum which is where the upper lip does not have a dip in the center.

KTS also presents itself with symptoms that affect the patient's ability to function. To varying degrees, patients either do not develop or have under developed language skills as well as under developed ambulance which is the ability to move around. Patients also present with global developmental delay. The severity of these symptoms is correlated with the intensity, frequency, and age of onset of the patient's epilepsy as well as their responsiveness to treatment for the epileptic attacks. In some severe cases, patients develop spastic tetraplegia which is the loss of function in all four limbs.

The extreme variability of symptoms was well represented in one family with 5 affected children. The first child was in a vegetative state and died at age 2. The second child showed psychomotor developmental delay at 1 month old, and epilepsy unresponsive to treatment at 9 months old. This child was also nonverbal and non ambulant. The third child's epilepsy was responsive to treatment and was ambulant, but she had an intellectual disability and only slight verbal abilities. The fourth child demonstrated developmental delay at age 6 months and had epileptic attacks that were only partially responsive to treatment. This child was non verbal and awkwardly ambulant. The fifth child was ambulant, but nonverbal and had epilepsy that was partially responsive to treatment. This variation has been seen across other cases of KTS as well.

ANOTHER syndrome consists of alopecia, nail dystrophy, ophthalmic complications, thyroid dysfunction, hypohidrosis, ephelides and enteropathy, and respiratory tract infections. This is an autosomal recessive variant of ectodermal dysplasia.

Lenz–Majewski syndrome is a skin condition characterized by hyperostosis, craniodiaphyseal dysplasia, dwarfism, cutis laxa, proximal symphalangism, syndactyly, brachydactyly, mental retardation, enamel hypoplasia, and hypertelorism.

In 2013, whole-exome sequencing showed that a missense mutation resulting in overactive phosphatidylserine synthase 1 was the cause of LMS, making it the first known human disease to be caused by disrupted phosphatidylserine metabolism. The researchers suggested a link between the condition and bone metabolism.

Associated symptoms range from things such as colobomas of the eyes, heart defects, ichthyosiform dermatosis, intellectual disability, and ear abnormalities. Further symptoms that may be suggested include characteristic facies, hearing loss, and cleft palate.

The differential diagnosis is quite extensive and includes

- Buschke–Fischer–Brauer disease

- Curth–Macklin ichthyosis

- Gamborg Nielsen syndrome

- Greither disease

- Haber syndrome

- Hereditary punctate palmoplantar keratoderma

- Jadassohn–Lewandowsky syndrome

- Keratosis follicularis spinulosa decalvans

- Keratosis linearis with ichthyosis congenital and sclerosing keratoderma syndrome

- Meleda disease

- Mucosa hyperkeratosis syndrome

- Naegeli–Franceschetti–Jadassohn syndrome

- Naxos disease

- Olmsted syndrome

- Palmoplantar keratoderma and leukokeratosis anogenitalis

- Pandysautonomia

- Papillomatosis of Gougerot and Carteaud

- Papillon–Lefèvre syndrome

- Punctate porokeratotic keratoderma

- Richner–Hanhart syndrome

- Schöpf–Schulz–Passarge syndrome

- Unna Thost disease

- Vohwinkel syndrome

- Wong's dermatomyositis

Genitopatellar syndrome is a rare condition characterized by genital abnormalities, missing or underdeveloped kneecaps (patellae), intellectual disability, and abnormalities affecting other parts of the body.

Genitopatellar syndrome is also associated with delayed development and intellectual disability, which are often severe. Affected individuals may have an unusually small head (microcephaly) and structural brain abnormalities, including underdeveloped or absent tissue connecting the left and right halves of the brain (agenesis of the corpus callosum).

The condition is also known by various other names:

- Lateral facial dysplasia

- First and second branchial arch syndrome

- Oral-mandibular-auricular syndrome

- Otomandibular dysostosis

- Craniofacial microsomia

Hypotrichosis–acro-osteolysis–onychogryphosis–palmoplantar keratoderma–periodontitis syndrome (also known as "HOPP syndrome") is a cutaneous condition characterized by a prominent palmoplantar keratoderma.

ADULT syndrome features include ectrodactyly, syndactyly, excessive freckling, lacrimal duct anomalies, dysplastic nails, hypodontia, hypoplastic breasts and nipples, hypotrichosis, hypohidrosis, broad nasal bridge, midfacial hypoplasia, exfoliative dermatitis, and xerosis. The lack of facial clefting and ankyloblepharon are important because they exist in ectrodactyly–ectodermal dysplasia–cleft syndrome (EEC) but not in ADULT syndrome.

Schöpf–Schulz–Passarge syndrome (also known as "eyelid cysts, palmoplantar keratoderma, hypodontia, and hypotrichosis") is an autosomal recessive condition with diffuse symmetric palmoplantar keratoderma, with the palmoplantar keratoderma and fragility of the nails beginning around age 12. In addition to palmoplantar keratoderma, other symptoms include hypodontia, hypotrichosis, nail dystrophies, and eyelid cysts (apocrine hidrocystomas). Patients may also develop syringofibroadenoma and squamous cell carcinomas.

It was characterized in 1971.

It has been associated with WNT10A.

Clinically, three distinct patterns of palmoplantar keratoderma may be identified: diffuse, focal, and punctate.