autosomal dominant

Watson Syndrome

Clinical Characteristics
Ocular Features: 

Iris nodules similar to those seen in neurofibromatosis are found in some but not all patients with Watson syndrome.

Systemic Features: 

Short stature and low normal intelligence are the most consistent features.  Pulmonic stenosis and cafe-au-lait spots are also common.   The macrocephaly is relative and not striking.  Neurofibromas have been seen in a minority of patients.

Genetics

Mutations in the NF1(17q11.2) gene have been identified in members of several large pedigrees with an apparent autosomal dominant pattern.

It remains uncertain if this condition is allelic to neurofibromatosis I(162200) or if Watson syndrome is the result of mutations in contiguous genes.

The LEOPARD syndrome(151100) shares some clinical similarities such as short stature, pulmonic stenosis, cognitive deficits and cafe-au-lait spots but is caused by mutations in PTPN11.   The phenotype also resembles Noonan syndrome in some aspects.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no known treatment for this condition but multidisciplinary management is recommended for isolated problems.

References
Article Title: 

Watson syndrome: is it a subtype of type 1 neurofibromatosis

Allanson JE, Upadhyaya M, Watson GH, Partington M, MacKenzie A, Lahey D, MacLeod H, Sarfarazi M, Broadhead W, Harper PS, et al. Watson syndrome: is it a subtype of type 1 neurofibromatosis? J Med Genet. 1991 Nov;28(11):752-6.

PubMed ID: 
1770531

LEOPARD Syndrome

Clinical Characteristics
Ocular Features: 

Ocular hypertelorism is a characteristic of all forms of the LEOPARD syndrome.  The lid fissures may be downward slanting.  Combined with the inverted triangle facies, the appearance is similar to that of the Noonan syndrome (163950).

Systemic Features: 

This is a multisystem disorder manifest in skin, heart, skeletal, genital, neurologic and auditory systems.  Generalized lentiginosis is characteristic but they may not be present until age 4 or 5 years following the appearance of cafe-au-lait spots.  Some patients have patchy scalp hair loss.  The facies bears some resemblance to the Noonan syndrome but usually without the short, webbed neck.  Sensorineural hearing loss is found in 20% of individuals.  Cardiac conduction defects, pulmonic stenosis, and hypertrophic cardiomyopathy are often (85%) present.  Cognitive defects are present in 30% of patients and some individuals have been described as mentally retarded.  Juvenile behavior may be evident in the presence of normal intelligence.  Hypospadias, cryptorchidism, and gonadal infantilism have been seen in some patients.  The ears are often malformed (87%).  Thoracic skeletal anomalies have been described in 75% of patients.  Although somatic growth is described as slow, short stature is present in less than half of patients.

Rare patients without lentigines are said to resemble the Noonan syndrome (163950) in appearance.

Genetics

Heterozygous mutations in the PTPN11 gene (12q24) are most frequently responsible for this autosomal dominant disorder.  The same gene is mutated in more than half of patients with the Noonan syndrome (NS1)(163950) with which it is allelic.  Other mutations that cause what is called LEOPARD syndrome are RAF1 and BRAF.

Other types of LEOPARD syndrome such as LEOPARD syndrome 2 (611554) are far more rare but also share mutations with Noonan syndrome (RAF1 mutations in Noonan syndrome 5) (611553) and LEOPARD syndrome 3 (613707) with mutations in BRAF similar to that seen in NS7 (613706).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Assistive hearing devices, especially cochlear implants, may be helpful.  Special education can be of value in more mildly affected individuals.Treatment of cryptorchidism is similar to that of other children.

References
Article Title: 

Waardenburg Syndrome, Type 3

Clinical Characteristics
Ocular Features: 

Type 3 Waardenburg syndrome has many of the features of other types but with the addition of upper limb anomalies.  Dystopia canthorum and a broad nasal root are characteristic.  Iris heterochromia is present in some patients.  Hypopigmentation may be seen in lashes and eyebrows.

Systemic Features: 

The upper limbs may appear underdeveloped with flexion contractures, fusion of the carpal bones and sometimes syndactyly.  A white forelock may or may not be present.  The cranial bones may be anomalous and rare patients can have microcephaly with significant mental retardation.  Mental function is usually normal though. Occasional patients have cleft palate and/or lip. Hearing loss is of the sensorineural type.  Hypopigmented skin patches are sometimes present but not all patients have them.

Genetics

The uniqueness of Waardenburg syndrome types 1 and 3 remains to be established.  Mutations in the PAX3 gene are responsible for both types and both have been found in the same family.  The phenotype is transmitted in an autosomal dominant pattern in either case but several families have been reported with type 1 WS in parents heterozygous for PAX3 mutations who had a homozygous child with the type 3 phenotype.  However, heterozygous individuals with type 3 have also been reported and the relationship of the two types remains unknown.

Craniofacial-deafness-hand syndrome(122880) with mutations in PAX3 has many features similar to those found in Waardenburg syndrome type 3 and may or may not be a unique disorder.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

There is no treatment for the syndrome but cochlear implants might be helpful.

References
Article Title: 

Craniofacial-Deafness-Hand Syndrome

Clinical Characteristics
Ocular Features: 

This rare syndrome has anomalies in periocular structures but not in the eye itself.  The lid fissures are downward slanting with telecanthus and hypertelorism.  The nasolacrimal duct was missing in several individuals.

Systemic Features: 

The midface is generally flat with underdeveloped maxillary bones and absent or small nasal bones but there may be frontal bossing.  The nose appears hypoplastic with a broad, flat root resulting in dystopia canthorum.  Micrognathia and a high arched palate are sometimes present.   The sinuses are often underdeveloped.  There may be ulnar deviation of the hands and fingers while flexion contractures and clinodactyly of the 5th finger are often present.  A sensorineural hearing loss is present in many individuals.  No poliosis has been reported.

Genetics

This is an autosomal dominant condition secondary to mutations in the PAX3 gene (22q36.1) in at least some patients.  Changes in the same gene are responsible for types 1 and 3 of the Waardenburg syndrome (193500, 148820).  In fact, the major mutation, a heterozygous C-to-G transversion, has been identified in the same codon in both CDHS and Waardenburg 3 (148820) patients.

More patients need to be genotyped to clarify the clinical features distinctive of Waardenburg types 1 and 3 (193500, 148820) and CDHS syndrome.  Should we consider these conditions allelic or simply the result of variable expressivity?  The appearance of the nasal root and associated structures is similar and both conditions are associated with sensorineural hearing loss.  Type 3 Waardenburg syndrome (148820) often has a cleft palate and musculoskeletal deformities of the upper limbs and fingers.  So far, no pigmentation changes have been reported in CDHS.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Surgical release of contractures could be considered.

References
Article Title: 

Cataracts, Congenital Zonular Pulverulent 3

Clinical Characteristics
Ocular Features: 

Bilateral dust-like lens opacities are diagnosed at a median age of 5 years but have been seen at 6 months of age.  These affect the embryonal, fetal, and infantile nucleus and are often surrounded by snowflake- or needle-like opacities throughout the lens cortex.  The dust-like particles may be multicolored and impart a haze to the lens.  Evidence for progression is suggested by the fact that about half of such affected patients require cataract surgery as adults.  No other ocular abnormalities are present.

There is considerable phenotypic heterogeneity.

Systemic Features: 

No systemic abnormalities are associated.

Genetics

Heterozygous mutations in GJA3 (13q11) seem to be responsible for the opacities.  For another somewhat similar form of autosomal dominant congenital cataract see Cataracts, Congenital Zonular Pulverulent 1 (116200).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Visually significant cataracts may be removed.

References
Article Title: 

Cataracts, CRYAA Mutations

Clinical Characteristics
Ocular Features: 

This seems to be a clinically heterogeneous group of lens opacities all due to mutations in the crystallin gene CRYAA.  Some patients also have colobomas and may have microcornea and corneal opacities.  The lens opacities are usually bilateral but there is considerable asymmetry in their morphology.  Opacities may be nuclear, polar, cortical, sutural, embryonal, and anterior subcapsular in location.  The cataracts are often present at birth.

Systemic Features: 

Systemic disease is absent.

Genetics

A variety of mutations in the CRYAA (21q22.3) have been reported in a several ethnic groups.  Most pedigrees are consistent with autosomal dominant inheritance but autosomal recessive inheritance has been suggested in other families.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Lens extraction may be necessary.

References
Article Title: 

Duane-Radial Ray Syndrome

Clinical Characteristics
Ocular Features: 

Most individuals have features of Duane’s anomaly, sometimes unilaterally.  Optic pallor with poor vision has been described in well-studied patients who also had thinning of the retinal nerve fiber layer.  The optic disk may appear hypoplastic.  Visual evoked potentials and pattern ERG amplitudes are decreased.

Other less common ocular features are microcornea, microphthalmia, ophthalmoplegia, hypertelorism, cataracts, epicanthal folds, colobomas, and chorioretinal scars.

Systemic Features: 

The systemic features are inconsistent (variable expressivity) with most patients having some variation of hypodactyly, polydactyly, syndactyly, and malformation of the hands.  The thumb is the most common digit involved and this is often associated with thenar hypoplasia.  Other skeletal features of the radial ray syndrome including absence of the radial and ulnar bones are variably present.  Hearing loss is described as sensorineural in etiology but malformations of the pinnae and external meatus are sometimes present.

Kidney anomalies include horseshoe malformations, abnormal rotation, ectopia, small size, vesicoureteric reflux, and pelvicalyceal dilatation.

Genetics

This is an autosomal dominant disorder due to heterozygous mutations in the SALL4 gene (20q13.2).

This syndrome is sometimes confused with the Holt-Oram syndrome but the latter is the result of mutations in a different gene and lacks ocular and renal abnormalities.  Duane syndrome 1 and 2 may also occur as isolated conditions.

The considerable clinical heterogeneity has led to alternate titles for this syndrome. For example, what is sometimes called the IVIC syndrome (147750) with similar features is also caused by mutations in this gene.  Duane-radial ray syndrome has also been called Okihiro syndrome. 

 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Treatment is symptomatic in most cases although reconstructive surgery may be helpful for severe hand deformities.  Low vision aids may be beneficial.  

References
Article Title: 

Nystagmus-Split Hand Syndrome

Clinical Characteristics
Ocular Features: 

The only consistent ocular finding is pendular nystagmus beginning at birth.  There is some evidence that the eye movements decrease with age.  Acuity in a 46 year old female was recorded to be 20/40 in each eye whereas one of her children had 20/70.  Two patients (father and daughter) have been described as having cataracts and “fundus changes”, not further defined.  Other patients have been described with normal fundi.  The ERG has been normal in several patients.  Some authors have noted hypertelorism.

The ocular phenotype requires further definition.  For example, in a single published photograph of a young child the medial portion of the eye brows is sparsely populated and all eyelashes in the medial one-third of the upper lid appear to be absent.  This has not been commented on in publications, however.

Systemic Features: 

The hand and foot malformation is severe, described as split-hand/split foot deformity.  It may involve all four extremities or just the upper extremity with monodactyly.  When the hand is involved, it may be called a lobster-claw deformity, or ectrodactyly.  The middle digit is characteristicly missing but other fingers and toes are sometimes absent.

The teeth erupt late, some may be missing and others are often poorly formed. Frontal bossing, sunken cheeks, and thick and everted lips may be part of the facial phenotype.

Genetics

The genetics of Karsch-Neugebauer is obscure although the majority of evidence is consistent with autosomal dominant inheritance.  Parent-child transmission and male-to-male transmission have been observed.  In other families the parents are normal but reduced penetrance has not been ruled out.  Further, there are several types of split-hand deformities but this is the only one associated with nystagmus.  No locus or mutation has been found for this condition.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Surgical reconstruction can sometimes improve hand function.

References
Article Title: 

Retinitis Pigmentosa 1

Clinical Characteristics
Ocular Features: 

Night blindness, the predominant presenting symptom, is often noted in the first decade of life but may not be a significant complaint until the third decade.  Concentric peripheral field loss likewise follows a similar timeline.  ERG responses progressively decrease in amplitude and may become undetectable in the second decade.  The retinal disease progresses relentlessly, albeit slowly, as the result of photoreceptor degeneration and most patients have severe visual handicaps by midlife but there is considerable clinical variation.  The pigmentary retinopathy is typical for classical retinitis pigmentosa with vascular attenuation, perivascular bone-spicule pigment clumping, optic atrophy, and generalized retinal atrophy with relative sparing of the macula early in the disease.  Lens opacities are common in late stages of the disease.

Systemic Features: 

No systemic disease is associated with the ocular disorder caused by mutations in RP1.

Genetics

Multiple heterozygous, homozygous, and compound heterozygous mutations in the RP1 gene (8q12.1), sometimes called the oxygen-regulated photoreceptor protein 1 or ORP1 gene, are responsible for this disorder.  The protein product is active specifically in retinal photoreceptors.  Retinitis pigmentosa 1 is generally considered to be an autosomal dominant disorder and accounts for 5-7% of dominantly inherited RP disease.  However, recent reports suggest that some mutations in RP1 are responsible for familial cases transmitted in an autosomal recessive pattern in which the clinical disease is more severe. 

More than 20 different mutant genes have been associated with autosomal dominant RP but many cases lack a family history suggesting additional genetic heterogeneity remains.  Reduced penetrance and variable expressivity characteristic of genetic disease likely contributes to the clinical heterogeneity as well.  For more about autosomal dominant retinitis pigmentosa, see Retinitis Pigmentosa, AD (180380, 268000).  

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Photoreceptor transplantation has been tried in a number of patients without improvement in central vision or interruption in the rate of vision loss.  Longer term results are needed.  Resensitizing photoreceptors with halorhodopsin using archaebacterial vectors shows promise in mice.  High doses of vitamin A palmitate slow the rate of vision loss but plasma levels and liver function need to be checked at least annually.  Oral acetazolamide can be helpful in reducing macular edema.

Low vision aids and mobility training can be facilitating for many patients.  Cataract surgery may restore several lines of vision at least temporarily.

Several pharmaceuticals should be avoided, including isotretinoin, sildenafil, and vitamin E.

References
Article Title: 

Révész Syndrome

Clinical Characteristics
Ocular Features: 

This is likely a severe form of dyskeratosis congenita with an exudative retinopathy in addition to the usual lid deformities, corneal opacification, conjunctival scarring.  The exudates are often present in early childhood, and may be of sufficient volume to present as leukocoria mimicking a retrolental mass.  The exudates extend through nearly all layers of the retina and are said to resemble Coats retinopathy. Vitreous hemorrhage and opacification has also been reported.  Severe vision loss and blindness may occur depending on the degree of retinal and vitreous disease.

Systemic Features: 

Patients with Revesz syndrome have cerebral calcifications, and hypoplasia of the cerebellum in addition to mild signs of dyskeratosis congenita such as a reticulated skin pattern, nail dysplasia, and oral leukoplakia.  Ataxia is a prominent sign but is not present in all patients.  Bone marrow failure with pancytopenia and a high risk of malignancies, however, are serious problems.  Aplastic anemia and neutropenia may present in early childhood while other signs may not appear until late childhood.  Sparse hair, intrauterine growth retardation and low birth weight are also features.   

Few patients with Revesz syndrome have been reported and the clinical features have not been fully delineated.  It is important to note that there is a large amount of clinical variation among patients.

Genetics

Heterozygous mutations in the TINF2 gene (14q12) have been found in Revesz syndrome.  Mutations in the same gene have also been found in the autosomal dominant form of dyskeratosis congenita (613990) suggesting that the two disorders, if distinct, are allelic.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Bone marrow failure may respond favorably to hematopoietic stem cell transplantation, at least for some time. Lifelong medical monitoring is required for the systemic and ocular disease.

References
Article Title: 

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