MedGen

Oral-facial-digital syndrome is actually a group of related conditions that affect the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes).

Other features occur in only one or a few types of oral-facial digital syndrome. These features help distinguish the different forms of the disorder. For example, the most common form of oral-facial-digital syndrome, type I, is associated with polycystic kidney disease. This kidney disease is characterized by the growth of fluid-filled sacs (cysts) that interfere with the kidneys' ability to filter waste products from the blood. Other forms of oral-facial-digital syndrome are characterized by neurological problems, particular changes in the structure of the brain, bone abnormalities, vision loss, and heart defects.

Researchers have identified at least 13 potential forms of oral-facial-digital syndrome. The different types are classified by their patterns of signs and symptoms. However, the features of the various types overlap significantly, and some types are not well defined. The classification system for oral-facial-digital syndrome continues to evolve as researchers find more affected individuals and learn more about this disorder.

The signs and symptoms of oral-facial-digital syndrome vary widely. However, most forms of this disorder involve problems with development of the oral cavity, facial features, and digits. Most forms are also associated with brain abnormalities and some degree of intellectual disability.

Abnormalities of the oral cavity that occur in many types of oral-facial-digital syndrome include a split (cleft) in the tongue, a tongue with an unusual lobed shape, and the growth of noncancerous tumors or nodules on the tongue. Affected individuals may also have extra, missing, or defective teeth. Another common feature is an opening in the roof of the mouth (a cleft palate). Some people with oral-facial-digital syndrome have bands of extra tissue (called hyperplastic frenula) that abnormally attach the lip to the gums.

Distinctive facial features often associated with oral-facial-digital syndrome include a split in the lip (a cleft lip); a wide nose with a broad, flat nasal bridge; and widely spaced eyes (hypertelorism).

Abnormalities of the digits can affect both the fingers and the toes in people with oral-facial-digital syndrome. These abnormalities include fusion of certain fingers or toes (syndactyly), digits that are shorter than usual (brachydactyly), or digits that are unusually curved (clinodactyly). The presence of extra digits (polydactyly) is also seen in most forms of oral-facial-digital syndrome. [from MedlinePlus Genetics]

Charcot-Marie-Tooth disease encompasses a group of disorders called hereditary sensory and motor neuropathies that damage the peripheral nerves. Peripheral nerves connect the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, heat, and sound. Damage to the peripheral nerves that worsens over time can result in alteration or loss of sensation and wasting (atrophy) of muscles in the feet, legs, and hands.

Charcot-Marie-Tooth disease usually becomes apparent in adolescence or early adulthood, but onset may occur anytime from early childhood through late adulthood. Symptoms of Charcot-Marie-Tooth disease vary in severity and age of onset even among members of the same family. Some people never realize they have the disorder because their symptoms are so mild, but most have a moderate amount of physical disability. A small percentage of people experience severe weakness or other problems which, in very rare cases, can be life-threatening. In most affected individuals, however, Charcot-Marie-Tooth disease does not affect life expectancy.

Typically, the earliest symptoms of Charcot-Marie-Tooth disease result from muscle atrophy in the feet. Affected individuals may have foot abnormalities such as high arches (pes cavus), flat feet (pes planus), or curled toes (hammer toes). They often have difficulty flexing the foot or walking on the heel of the foot. These difficulties may cause a higher than normal step (steppage gait) and increase the risk of ankle injuries and tripping. As the disease worsens, muscles in the lower legs usually weaken, but leg and foot problems rarely require the use of a wheelchair.

Affected individuals may also develop weakness in the hands, causing difficulty with daily activities such as writing, fastening buttons, and turning doorknobs. People with Charcot-Marie-Tooth disease typically experience a decreased sensitivity to touch, heat, and cold in the feet and lower legs, but occasionally feel aching or burning sensations. In rare cases, affected individuals have loss of vision or gradual hearing loss that sometimes leads to deafness.

There are several types of Charcot-Marie-Tooth disease, which are differentiated by their effects on nerve cells and patterns of inheritance. Type 1 (CMT1) is characterized by abnormalities in myelin, the fatty substance that covers nerve cells, protecting them and helping to transmit nerve impulses. These abnormalities slow the transmission of nerve impulses and can affect the health of the nerve fiber. Type 2 (CMT2) is characterized by abnormalities in the fiber, or axon, that extends from a nerve cell body to muscles or to sense organs. These abnormalities reduce the strength of the nerve impulse. People with CMT2 may develop amyotrophic lateral sclerosis (ALS), a condition characterized by progressive muscle weakness, a loss of muscle mass, and an inability to control movement.In forms of Charcot-Marie-Tooth disease classified as intermediate type, the nerve impulses are both slowed and reduced in strength, probably due to abnormalities in both myelin and axons. Type 4 (CMT4) is distinguished from the other types by its pattern of inheritance; it can affect either the axons or the myelin. Type X Charcot-Marie-Tooth disease (CMTX) is caused by mutations in genes on the X chromosome, one of the two sex chromosomes. Within the various types of Charcot-Marie-Tooth disease, subtypes (such as CMT1A, CMT1B, CMT2A, CMT4A, and CMTX1) indicate different genetic causes.

Sometimes other, historical names are used to refer to particular forms of  Charcot-Marie-Tooth disease. For example, Roussy-Levy syndrome is a form of CMT11 with the additional feature of rhythmic shaking (tremors).  Dejerine-Sottas syndrome is a term sometimes used to describe a severe, early childhood form of Charcot-Marie-Tooth disease; it is also sometimes called type 3 (CMT3). Depending on the specific gene that is altered, this severe, early-onset form of the disorder may also be classified as CMT1 or CMT4. CMTX5 is also known as Rosenberg-Chutorian syndrome. [from MedlinePlus Genetics]

48,XXYY syndrome is a chromosomal condition that affects development in people who are assigned male at birth. There is a lot of variability in symptoms between people with 48,XXYY syndrome. Almost all affected individuals have developmental delays in infancy and develop decreased testosterone levels (hypogonadism) during adolescence. People with 48,XXYY syndrome are also at risk for other health problems.

 Adolescents and adults with this condition usually have small testes that do not produce enough testosterone, which is the hormone that directs male sexual development. Without treatment, a shortage of testosterone during puberty can lead to reduced facial and body hair, poor muscle development, low energy levels, and an increased risk of breast enlargement (gynecomastia). Because their testes do not function normally, individuals with 48,XXYY syndrome have difficulty having biological children (a condition called infertility), but they may be able to have children using assisted reproductive technologies. 

48,XXYY syndrome can affect other parts of the body as well. Affected individuals are often taller than their peers, with an average adult height of 6 feet, 4 inches (193 cm). They may develop a mild to moderate hand tremor that typically starts in adolescence and may increase with age. Dental problems are frequently seen in people with this condition,  including delayed appearance of the primary (baby) or secondary (adult) teeth, thin tooth enamel, crowded or misaligned teeth, and multiple cavities. 

Additionally, individuals with 48,XXYY syndrome may have flat feet (pes planus), elbow abnormalities, abnormal fusion of certain bones in the forearm (radioulnar synostosis), allergies, asthma, type 2 diabetes, seizures, congenital heart defects, and an inflammatory condition in the throat (esophagus) called eosinophilic esophagitis. As people with 48,XXYY get older, they may develop a narrowing of the blood vessels in the legs called peripheral vascular disease. Peripheral vascular disease can cause skin ulcers to form. Affected individuals are also at risk of developing a type of clot called a deep vein thrombosis that occurs in the deep veins of the legs. 

Most individuals with 48,XXYY syndrome have an IQ score that ranges from 60 to 80 and have some degree of difficulty with speech and language development. The development of motor skills such as sitting, standing, and walking may be delayed in some children with 48,XXYY syndrome. They may also have poor coordination. Learning disabilities are very common in people with this disorder, especially in the areas of reading and written expression. People with 48,XXYY typically perform better at tasks focused on math, visual-spatial skills such as puzzles, and memorization of locations or directions. Affected individuals have higher-than-average rates of other neurodevelopmental and behavioral disorders, such as attention-deficit/hyperactivity disorder (ADHD); mood disorders, including anxiety and depression; and autism spectrum disorder, which affects communication and social interaction. [from MedlinePlus Genetics]

EEG without electrical activity. [from HPO]

Epidermodysplasia verruciformis-4 is an autosomal recessive immunologic disorder characterized by increased susceptibility to certain human papilloma viruses (HPV) that cause warts and skin lesions. Affected individuals present in childhood with disseminated flat warts and psoriatic-like lesions that do not respond to treatment. Immunologic workup shows defects in T-cell development and signaling (summary by Crequer et al., 2012). For a discussion of genetic heterogeneity of susceptibility to epidermodysplasia verruciformis, see EV1 (226400). [from OMIM]

Trisomy 4p is a rare chromosomal anomaly syndrome, resulting from the partial duplication of the short arm of chromosome 4, with a highly variable phenotype, typically characterized by pre- and postnatal growth delay, psychomotor developmental delay and craniofacial dysmorphism (microcephaly, prominent glabelle, hypertelorism, enlarged ears with abnormal helix and antihelix, bulbous nose with flat or depressed nasal bridge, long philtrum, retrognathia with pointed chin). Additional features include skeletal (rocker bottom feet, arachnodactyly, camptodactyly) and renal malformations, cardiac defects, ocular abnormalities and abnormal genitalia in males. [from ORDO]

The focal dermal dysplasias (FFDDs) are a group of related developmental defects characterized by bitemporal or preauricular skin lesions resembling aplasia cutis congenita. Cervantes-Barragan et al. (2011) proposed a classification of FFDD in which there are 4 subtypes. FFDD1 (Brauer syndrome) is characterized by temporal skin depressions that resemble 'forceps marks.' Other facial anomalies, comprising sparse lateral eyebrows, distichiasis, and a flattened nasal tip, are usually mild. Inheritance is autosomal dominant. FFFD2 (Brauer-Setleis syndrome; 614973) is characterized by bitemporal skin lesions with variable facial findings, including thin and puckered periorbital skin, distichiasis and/or absent eyelashes, upslanting palpebral fissures, a flat nasal bridge with a broad nasal tip, large lips, and redundant facial skin. Inheritance is autosomal dominant. FFDD3 (Setleis syndrome; 227260) is characterized by the same facial features as FFDD2, but the inheritance is autosomal recessive. FFDD4 (614974) is characterized by isolated, preauricular skin lesions with autosomal dominant or recessive inheritance (summary by Slavotinek et al., 2013). Genetic Heterogeneity of Focal Facial Dermal Dysplasia FFDD3 (227260) is caused by mutation in the TWIST2 gene (607556) on chromosome 2q37. FFDD4 (614974) is caused by mutation in the CYP26C1 gene on chromosome 10q23. [from OMIM]

The ilia is round and hypoplastic with a very flat acetabular roof and a very unusual medial projection of bone that is said to resemble the head of a snail. Figure 4 of PMID:3799723 illustrates this feature. [from HPO]

An extremely rare autosomal anomaly resulting from the presence of 4 copies of chromosome 21. The disease is characterised by features of trisomy 21 including developmental delay/intellectual disability, muscular hypotonia, short neck with redundant skin, brachycephaly, microcephaly, flat face, epicanthus, upslanted palpebral fissures, small ears, protruding tongue, single transverse palmar crease, brachydactyly, hypoplastic iliac wings, together with additional features such as prematurity, intrauterine growth retardation, high and broad forehead, hypertelorism. Haematological malignancies are also associated and may occur earlier than in trisomy 21. [from SNOMEDCT_US]