Manifestations include enlarged viscera, hepatomegaly, diabetes, short stature and cranial hyperostosis.

Katz Syndrome is a rare congenital disorder, presenting as a polymalformative syndrome characterized by enlarged viscera, hepatomegaly, diabetes, and skeletal anomalies that result in a short stature, cranial hyperostosis, and typical facial features. It is probably a variant of the autosomal recessive type of Craniometaphyseal Dysplasia.

Signs and symptoms include:

- syndromic facies

- hearing loss

- facial paralysis

This condition is characterised by symmetrical lesions on the temples resembling forceps marks. It is characterized a puckered skin due to a virtual absence of subcutaneous fat. It is apparent at birth. Other lesions that may be present include puffy, wrinkled skin around the eyes and/or abnormalities of the eyelashes, eyebrows, and eyelids. The eyebrows may be up slanting or outward slanting. Occasionally the bridge of the nose may appear flat, while the tip may appear unusually rounded. The chin may be furrowed. The upper lip may be prominent with a down turned mouth. Other features that have been reported include dysplastic and low set ears, linear radiatory impressions on the forehead and congenital horizontal nystagmus.

Those with the Setleis syndrome may be missing eyelashes on both the upper and lower lids or may have multiple rows of lashes on the upper lids but none on the lower lids.A possible association with intra abdominal cancer has been reported but to date this has not been confirmed in other studies.

Zori–Stalker–Williams syndrome, also known as pectus excavatum, macrocephaly, short stature and dysplastic nails, is a rare autosomal dominant congenital disorder associated with a range of features such as pectus excavatum, macrocephaly and dysplastic nails, familial short stature, developmental delay and distinctive facies. Further signs are known to be associated with this syndrome.

The name originates from the researchers who first defined and noticed the syndrome and its clinical signs.

It is believed that the syndrome is inherited in an autosomal dominant pattern, though there has been no new research undertaken for this rare disease.

Worth syndrome, also known as benign form of Worth hyperostosis corticalis generalisata with torus platinus, autosomal dominant osteosclerosis, autosomal dominant endosteal hyperostosis or Worth disease, is a rare autosomal dominant congenital disorder that is caused by a mutation in the LRP5 gene. It is characterized by increased bone density and benign bony structures on the palate.

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.

Focal facial dermal dysplasia (FFDD) is a rare genetically heterogeneous group of disorders that are characterized by congenital bilateral scar like facial lesions, with or without associated facial anomalies. It is characterized by hairless lesions with fingerprint like puckering of the skin, especially at the temples, due to alternating bands of dermal and epidermal atrophy.

This condition is also known as Brauer syndrome (hereditary symmetrical aplastic nevi of temples, bitemporal aplasia cutis congenita, bitemporal aplasia cutis congenita: OMIM ) and Setleis syndrome (facial ectodermal dysplasia: OMIM ).

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.

Lhermitte–Duclos disease (LDD) (), also called dysplastic gangliocytoma of the cerebellum, is a rare, slowly growing tumor of the cerebellum, a gangliocytoma sometimes considered to be a hamartoma, characterized by diffuse hypertrophy of the granular layer of the cerebellum. It is often associated with Cowden syndrome. It was described by Jacques Jean Lhermitte and P. Duclos in 1920.

Craniometaphyseal dysplasia is diagnosed based on clinical and radiographic findings that include hyperostosis. Some things such as cranial base sclerosis and nasal sinuses obstruction can be seen during the beginning of the child's life. In radiographic findings the most common thing that will be found is the narrowing of foramen magnum and the widening of long bones. Once spotted treatment is soon suggested to prevent further compression of the foramen magnum and disabling conditions.

Mandibuloacral dysplasia is a rare autosomal recessive syndrome characterized by mandibular hypoplasia, delayed cranial suture closure, dysplastic clavicles, abbreviated and club-shaped terminal phalanges, acroosteolysis, atrophy of the skin of the hands and feet, and typical facial changes.

Types include:

Facial femoral syndrome is a rare congenital disorder. It is also known as femoral dysgenesis, bilateral femoral dysgenesis, bilateral-Robin anomaly and femoral hypoplasia-unusual facies syndrome. The main features of this disorder are underdeveloped thigh bones (femurs) and unusual facial features.

Acro–dermato–ungual–lacrimal–tooth (ADULT) syndrome is a rare genetic disease. ADULT syndrome is an autosomal dominant form of ectodermal dysplasia, a group of disorders that affects the hair, teeth, nails, sweat glands, and extremities. The syndrome arises from a mutation in the TP63 gene. This disease was previously thought to be a form of ectrodactyly–ectodermal dysplasia–cleft syndrome (EEC), but was classified as a different disease in 1993 by Propping and Zerres.

TBS patients may have the following symptoms:

- Abnormalities of the external ears (unusually large or small, unusually shaped, sometimes with sensorineural hearing loss or deafness due to lesions or dysfunctions of part of the internal ear or its nerve tracts and centers or conductive hearing loss from the external or middle ear), dysplastic ears, lop ear (over-folded ear helix), preauricular tags or pits (a rudimentary tag of ear tissue typically located just in front of the ear).

- Anorectal malformations, including imperforate anus/absence of an anal opening, rectovaginal fistula, anal stenosis, unusually placed anus.

- Renal abnormalities, sometimes leading to impaired renal function or renal failure, including hypoplastic kidneys (underdeveloped), multicystic kidneys, dyspastic kidneys.

- Heart abnormalities, including tetralogy of fallot and defects of the ventricular septum.

- Hand and foot abnormalities, such as hypoplastic thumbs, fingerlike thumbs, syndactyly (webbed fingers/toes), fusion of the wrist bones, overlapping foot and/or toe bones.

Learning difficulties have been reported in some children with TBS. For others, intelligence is within the normal range.

These abnormalities, which are present prenatally, can range from minor to severe, and as with similar disorders, most individuals with this condition have some, but not all, of these traits.

Patients with CED complain of chronic bone pain in the legs or arms, muscle weakness (myopathy) and experience a waddling gait. Other clinical problems associated with the disease include increased fatigue, weakness, muscle spasms, headache, difficulty gaining weight, and delay in puberty. Some patients have an abnormal or absent tibia, may present with a flat foot, or scoliosis.

This disease may also cause bones to become abnormally hardened which is referred to as sclerosis. This hardening may affect the bones at the base of the skull or those in the hands, feet, or jaw. This causes ongoing pain and aching within the body parts that are affected. The pain has been described as either a hot electric stabbing pain, an ever-increasing pressure sensation around the bones (especially before electrical storms) or as a constant ache that radiates through several long bones at once. Pain may also occur in the hips, wrists, knees and other joints as they essentially just 'lock-up' (often becoming very stiff, immobile and sore), mostly when walking up or down staircases, writing for extended periods of time, or during the colder months of the year. Those with the disease tend to have a very characteristic walk medically diagnosed as a 'waddling gait'. This is observed by the broad-based gait with a duck-like waddle to the swing phase, the pelvis drops to the side of the leg being raised, notable forward curvature of the lumbar spine and a marked body swing.

The pain is especially severe during a 'flare-up', these can be unpredictable, exhausting and last anywhere from a few hours to several weeks. This is a common occurrence for several CED patients, often causing myopathy and extensive sleep deprivation from the chronic, severe and disabling pain. Patients may even require the use of a wheelchair (or additional carer's help with getting dressed, showering, mobility/shopping, preparing meals or lifting heavy items) especially when bedridden or housebound for days or weeks at a time. 'Flare-ups' may be attributed to, or exacerbated by growth spurts, stress, exhaustion, exercise, standing or walking for too long, illness, infection, being accidentally knocked/hurt or injured, after surgery/anaesthetics, cold weather, electrical storms, and sudden changes in barometric pressure.

CED may also affect internal organs, the liver and spleen, which may become enlarged. A loss of vision and/or hearing can occur if bones are adversely affected by the hardening in the skull. Hence proactive specialist check-ups, X-rays, diagnostic tests/scans, and regular blood tests are recommended on an annual basis to monitor the CED bony growth and secondary medical issues that may arise from this condition.

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

Main clinical signs and symptoms include:

- headache

- movement disorders

- tremor

- visual disturbances

- abnormal EEG

- Diplopia

Patients with Lhermitte–Duclos disease and Cowden's syndrome may also have multiple growths on skin. The tumor, though benign, may cause neurological injury including abnormal movements.

MICROSCOPY(lhermitte-duclos disease)

1>Enlarged circumscribed cerebellar folia

2>internal granular layer is focally indistinct and is occupied by large ganglion cells

3>myelinated tracks in outer molecular layer

4>underlying white matter is atrophic and gliotic

Microlissencephaly Type B or Barth microlissencephaly syndrome: is a microlissencephaly with thick cortex, severe cerebellar and brainstem hypoplasia. The Barth-type of MLIS is the most severe of all the known lissencephaly syndromes.

This phenotype consists of polyhydramnios (probably due to poor fetal swallowing), severe congenital microcephaly, weak respiratory effort, and survival for only a few hours or days. Barth described two siblings with this type as having a very low brainweight, wide ventricles, a very thin neopallium, absent corpus callosum and absent olfactory nerve.

Microlissencephaly with mildly to moderately thick (6–8 mm) cortex, callosal agenesis

Camurati–Engelmann disease (CED) is a very rare autosomal dominant genetic disorder that causes characteristic anomalies in the skeleton.It is also known as progressive diaphyseal dysplasia. It is a form of dysplasia. Patients typically have heavily thickened bones, especially along the shafts of the long bones (called diaphyseal dysplasia). The skull bones may be thickened so that the passages through the skull that carry nerves and blood vessels become narrowed, possibly leading to sensory deficits, blindness, or deafness.

This disease often appears in childhood and is considered to be inherited, however some patients have no previous history of CED within their family. The disease is slowly progressive and, while there is no cure, there is treatment.

It is named for M. Camurati and G. Engelmann.

An affected infant typically has the following triad of signs and symptoms: soft-tissue swelling, bone lesions, and irritability. The swelling occurs suddenly, is deep, firm, and may be tender. Lesions are often asymmetric and may affect several parts of the body. Affected bones have included the mandible, tibia, ulna, clavicle, scapula, ribs, humerus, femur, fibula, skull, ilium, and metatarsals. When the mandible (lower jaw bone) is affected, infants may refuse to eat, leading to failure to thrive.

The diagnosis is based on the combination of unusual facial features and the dysplastic or absent femurs.

Diagnosis may be made antenatally.

Hematologic manifestations related to bone marrow suppression and subsequent pancytopenia are a major source of morbidity and mortality. Additionally extramedullary hematopoiesis can result in liver and spleen dysfunction. Cranial nerve dysfunction and neurologic complications are usually associated with infantile osteopetrosis. Expansion of the skull bone leads to macrocephaly. Additionally, linear growth retardation that is not apparent at birth, delayed motor milestones and poor dentition can occur.

Malignant infantile osteopetrosis, also known as infantile autosomal recessive osteopetrosis or simply infantile osteopetrosis is a rare osteosclerosing type of skeletal dysplasia that typically presents in infancy and is characterized by a unique radiographic appearance of generalized hyperostosis - excessive growth of bone.

The generalized increase in bone density has a special predilection to involve the medullary portion with relative sparing of the cortices. Obliteration of bone marrow spaces and subsequent depression of the cellular function can result in serious hematologic complications. Optic atrophy and cranial nerve damage secondary to bony expansion can result in marked morbidity. The prognosis is extremely poor in untreated cases. Plain radiography provides the key information to the diagnosis. Clinical and radiologic correlations are also fundamental to the diagnostic process, with additional gene testing being confirmatory.