hydrocephalus

Anterior Segment, Brain, and Facial Anomalies

Clinical Characteristics
Ocular Features: 

The interpupillary distance appears abnormally wide.  VEP and ERG responses suggest abnormal retinal bipolar cells.  Specular microscopy reveals variable sizes and shapes of corneal endothelial cells with scattered vesicles and large 'holes' in the usual hexagonal array.  The iris may be malformed (no collarette, stromal hypoplasia) and there may be peripheral iridocorneal adhesions.  Elevated IOP, band keratopathy, corneal clouding, and keratoconus have been reported.  Visual acuity is impaired to some extent, from near normal (20/25) to NLP.  Progressive optic atrophy was observed in one patient.

Systemic Features: 

Four members of a 3 generation family had malformed pinnae (posterior placement and rotation).  Other features variably present were an empty sella turcica, posterior fossa cyst, and hydrocephalus. The propositus also was found to have abnormal auditory bipolar cells based on the audiogram and audio-evoked brainstem responses.

Genetics

Based on direct sequencing in one family (3 adults and 1 child), this condition seems to be caused by heterozygous variations or mutations in the VSX1 gene (20p11.21). 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Monitoring for glaucoma and appropriate treatment are indicated.  Hearing tests should be performed early.  The usual treatments for keratoconus should be considered.  Excess brain fluid may need surgical drainage.

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References
Article Title: 

Cole-Carpenter Syndrome 1

Clinical Characteristics
Ocular Features: 

The bony orbits are shallow and the eyes appear prominent as part of the facial and skull bone deformities.  The proptosis may be progressive and eventually interfere with blinking and normal surface wetting of the cornea. 

Systemic Features: 

This condition may superficially resemble osteogenesis imperfecta with osseous deformities and frequent fractures.  However, the occurrence of craniosynostosis and hydrocephalus helps to distinguish it.  Cranial sutures may be slow to fuse and macrocephaly has been described.  Communicating hydrocephalus can be a feature and may require shunting.  Some patients have osteopenia of the long bones that fracture easily.

The facial features are said to be distinctive with midface hypoplasia, low-set ears, micrognathia, and, of course, prominent globes.  Growth may be subnormal and a variety of limb bone and digital anomalies have been described.  Intelligence is normal, however.

Genetics

This condition is the result of heterozygous mutations in the P4HB gene (17q25.3) (PDI family).

See Cole-Carpenter Syndrome 2 (616294) for a somewhat similar disorder that is recessively inherited.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

A frontal craniectomy may be necessary during early childhood to relieve the proptosis particularly when blinking is impaired.  Patients must be followed for the development of communicating hydrocephalus.  Long bone fractures require prompt treatment. 

References
Article Title: 

Beare-Stevenson Syndrome

Clinical Characteristics
Ocular Features: 

The midface hypoplasia and shallow orbits result in the appearance of prominent eyes.  Ptosis and hypertelorism have been reported while the palpebral fissures are downslanting. One patient has been reported to have optic atrophy.  Another patient was described with cloudy corneas, irregular irides and nonreactive pupils.

Systemic Features: 

Pregnancies may be complicated by polyhydramnios.  Infants are born with craniosynostosis with a cloverleaf pattern usually.  The skull is often shortened in the anteroposterior axis with flattening of the occipital region.  The skin is deeply furrowed with the cutis gyrata patterns most prominent in the posterior scalp but also present on the palms, soles, pinnae, and elsewhere.  Acanthosis nigricans is often present.

There is midface hypoplasia and nearly all individuals have intellectual disability.

The external ear canals can be atretic, the nares are often anteverted, and the mouth may be small.  An excess number of neonatal teeth and hypoplastic nails have been noted.  Hydrocephalus is common.  The umbilical stump is often unusually prominent.  Anogenital anomalies such as an anteriorly placed anus, cryptorchidism, and bifid scrotum may be present.  Pyloric stenosis is sometimes present.

Upper airway obstruction with respiratory distress may necessitate a tracheotomy. A cartilaginous tracheal sleeve replacing the normal C rings of cartilage has been found in several infants. These can be difficult to detect and their presence may have been responsible for breathing restrictions that has led to the demise of some children before two years of age.

Genetics

Reported cases have occurred sporadically.  Increased paternal age has been suggested as a factor in the occurrence of heterozygous mutations in the FGFR2 gene (10q26.13) which have been identified in some individuals.

Other forms of craniosynostosis in which mutations in FGFR2 have been found are: Crouzon Syndrome (123500), Pfeiffer Syndrome (101600), Apert Syndrome (101200), Jackson-Weiss Syndrome (123150), and Saethre-Chotzen Syndrome (101400).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no general treatment for this syndrome.  Several infants have had tracheotomies and CNS shunts.

References
Article Title: 

Beare-Stevenson cutis gyrata syndrome

Hall BD, Cadle RG, Golabi M, Morris CA, Cohen MM Jr. Beare-Stevenson cutis gyrata syndrome. Am J Med Genet. 1992 Sep 1;44(1):82-9. PubMed PMID: 1519658.

PubMed ID: 
1519658

Osteogenesis Imperfecta, Type VII

Clinical Characteristics
Ocular Features: 

Shallow orbits sometimes lead to severe and even progressive proptosis.  Bluish sclerae are sometimes present.

Systemic Features: 

Infants may be born with multiple fractures and adults are often short in stature.  Hypoplasia of the midface, frontal bossing, sutural craniosynostosis, hydrocephalus, and shallow orbits are frequently present and contribute to what is sometimes considered a distinctive facial dysmorphism.  Dentinogenesis imperfecta and hearing loss are variable features.  Neurological development is normal.

Multiple fractures occur and may result in marked long bone deformities, scoliosis, and short stature.  When the ribs are involved, respiratory insufficiency may result and can be responsible for early death.  Type VII osteogenesis imperfecta is sometimes considered a lethal form of OI. 

Genetics

Homozygous mutations in the CRTAP gene (3p22.3) are responsible for this condition.  This gene codes for a cartilage-associated protein and in mice is highly expressed in chondrocytes at growth plates and around the chondroosseous junction.  

This condition has been confused with Cole-Carpenter 1 syndrome (112240) but the latter is due to heterozygous mutations in P4HB (17q25.3) (PDI gene family).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Fractures require stabilization and hydrocephalus, if present, needs to be treated promptly.  Extreme proptosis can lead to inadequate hydration of the eye (especially the cornea) that may require lid surgery or orbital reconstruction.

References
Article Title: 

CRTAP mutation in a patient with Cole-Carpenter syndrome

Balasubramanian M, Pollitt RC, Chandler KE, Mughal MZ, Parker MJ, Dalton A, Arundel P, Offiah AC, Bishop NJ. CRTAP mutation in a patient with Cole-Carpenter syndrome. Am J Med Genet A. 2015 Jan 21. doi: 10.1002/ajmg.a.36916. [Epub ahead of print].

PubMed ID: 
25604815

New case of Cole-Carpenter syndrome

Amor DJ, Savarirayan R, Schneider AS, Bankier A. New case of Cole-Carpenter syndrome. Am J Med Genet. 2000 Jun 5;92(4):273-7. Review.

PubMed ID: 
10842295

Walker-Warburg Syndrome

Clinical Characteristics
Ocular Features: 

The eyes are usually small and contain either retinal dysplasia or a congenital retinal detachment.  Colobomas, PHPV, cataracts, glaucoma, buphthalmos, anterior chamber dysgenesis, optic atrophy, and optic nerve hypoplasia have also been reported. 

Systemic Features: 

Hydrocephalus and congenital muscular dystrophy are the most important systemic features of these syndromes.  A Dandy-Walker malformation is often present.  Type II lissencephaly, cerebellar malformations and severe mental retardation are other features.  More variable signs include macro- or microcephaly, ventricular dilatation, cleft lip and/or palate, and congenital contractures.  WWS has a severe phenotype and death often occurs in the first year of life.  Brain histology shows severely disorganized cytoarchitecture and suggests a neuronal migration disorder. Microtia has been reported in several patients.

Most developmental milestones are delayed or never achieved and death may occur in early childhood. 

Genetics

The MDDGs (muscular dystrophy dystroglycanopathies) comprise a genetically and clinically heterogeneous group of disorders (sometimes called muscle-eye-brain disease) of which the A types are more severe than the B types.  The mutant genes responsible are involved in glycosylation of DAG1 (alpha-dystroglycan). 

Types A1 (MDDGA1; 236670), B1 (MDDGB1; 613155) and C1 (MDDGC1; 609308) result from mutations in a gene known as POMT1 (9p34.1).  The muscular dystrophy in type C1 is of the limb-girdle type LGMD2K.

A2 (MDDGA2; 613150) is caused by mutations in POMT2 (14q24.3).  Mutations in POMT2 may also cause the less severe muscle-eye-brain disease (MEB) type B2 (MDDGB2; 613156), and a similar disease (C2) in which the muscle dystrophy is of the limb-girdle type LGMD2N and eye findings may be absent (MDDGC2; 613158).

Mutations in POMGNT1 (1p34-p33) cause type A3 (MDDGA3; 253280) and type B3 (MDDGB3; 613151).  The muscular dystrophy in B3 is of the limb-girdle type.  POMGNT1 mutations may be associated with congenital glaucoma, retinal dysplasia, and high myopia. Type C3 (MDDGC3; 613157), also with a limb-girdle type of muscular dystrophy (LGMD2O), is caused by mutations in POMGNT1 as well.

FKTN mutations cause type A4 MDDG (MDDGA4; 253800) associated with the Fukuyama type of congenital muscular dystrophy but they can also cause type B4 (MDDGB4; 613152) which does not have mental retardation, and type C4 (MDDGC4; 611588) with seizures and a limb-girdle type (LGMD2M) of muscular dystrophy.

Types A5 (MDDG5A; 613153) and B5 (MDDGB5; 606612) are the result of mutations in the FKRP gene (19q13.3).  Of the two the latter is the less severe and the muscular dystrophy is of the limb-girdle type.  The eyes may be microphthalmic and have retinal pigmentary changes and congenital glaucoma.

Type A6 (MDDGA6; 613154) and B6 (MGGDB6; 608840) are caused by mutations in the LARGE gene (22q12.3).  MDDGA7, or type A7 (614643) results from homozygous or compound heterozygous mutations in the ISPD gene.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No effective treatment is available but early indications are that FKRP gene therapy restores functional glycosylation and improves muscle functions.

References
Article Title: 

Congenital muscular dystrophies with defective glycosylation of dystroglycan: a population study

Mercuri E, Messina S, Bruno C, Mora M, Pegoraro E, Comi GP, D'Amico A, Aiello C, Biancheri R, Berardinelli A, Boffi P, Cassandrini D, Laverda A, Moggio M, Morandi L, Moroni I, Pane M, Pezzani R, Pichiecchio A, Pini A, Minetti C, Mongini T, Mottarelli E, Ricci E, Ruggieri A, Saredi S, Scuderi C, Tessa A, Toscano A, Tortorella G, Trevisan CP, Uggetti C, Vasco G, Santorelli FM, Bertini E. Congenital muscular dystrophies with defective glycosylation of dystroglycan: a population study. Neurology. 2009 May 26;72(21):1802-9.

PubMed ID: 
19299310

Conjunctivitis, Ligneous

Clinical Characteristics
Ocular Features: 

The most common clinical feature of this disorder is conjunctivitis often precipitated by an injury or infection of the conjunctiva with typical inflammatory features.   A thick, ligneous (wood-like) pseudomembrane containing clotted fibrin subsequently forms that appears white, yellow-white, or finally red.  These can be surgically removed but tend to recur, often on an accelerated timescale.  This process is most pronounced on the upper tarsal conjunctiva but often involves the bulbar conjunctiva and the cornea as well.  Corneal involvement (in nearly a third of cases) can lead to vascularization, scarring, keratomalacia, and perforation.  The disease may be intermittent. 

Systemic Features: 

While the conjunctiva is most commonly involved, other mucosal surfaces such as oral, laryngeal, tracheal, and vaginal mucosas may have similar disease often concomitantly with the ocular lesions.  Ligneous gingivitis consists of nodular lesions with ulceration and peridodontal tissue destruction.  The ear may also be involved in the disease.   Life-threatening airway obstruction is a threat, especially in children during acute recurrences.  Occlusive hydrocephalus requiring shunting occurs in a significant number of affected children. 

Genetics

This autosomal recessive condition seems to result from homozygous mutations in the PLG gene (6q26) that codes for plasminogen.  Tears contain plasminogen activators that convert plasminogen into the fibrinolytic enzyme plasmin which normally clears conjunctival and corneal fibrin deposits.  The lack of normal plasminogen allows fibrin to accumulate on all mucosal surfaces. 

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Four weeks of treatment with IV human Glu-plasminogen in a small group of children and adults with congenital plasminogen deficiency produced marked clinical improvement in ocular as well as disseminated symptoms according to a recent report. 

Surgical excision of the pseudomembrane is possible but multiple recurrences are common. Spontaneous resolution has been reported.

References
Article Title: 

Treatment of plasminogen deficiency patients with fresh frozen plasma

Kizilocak H, Ozdemir N, Dikme G, Koc B, Atabek AA, Cokugras H, Iskeleli G, Donmez-Demir B, Christiansen NM, Ziegler M, Ozdag H, Schuster V, Celkan T. Treatment of plasminogen deficiency patients with fresh frozen plasma. Pediatr Blood Cancer. 2017 Sep 6. doi: 10.1002/pbc.26779. [Epub ahead of print].

PubMed ID: 
28876531

Ligneous conjunctivitis

Schuster V, Seregard S. Ligneous conjunctivitis. Surv Ophthalmol. 2003 Jul-Aug;48(4):369-88. Review.

PubMed ID: 
12850227

Biemond Syndrome II

Clinical Characteristics
Ocular Features: 

This disorder may belong to the spectrum of Bardet-Biedl syndromes (209900) but is listed separately because of the prominent association of iris colobomata.  Retinal dystrophy resembling retinitis pigmentosa is also part of this disorder but the rarity of cases precludes a full description of the phenotype.

Systemic Features: 

Underdevelopment of the external genitalia is more prominent in males.  Obesity, hydrocephalus and mental retardation are also features.  Postaxial polydactyly is common.  Renal disease does not seem to be part of this disorder.

Genetics

Little is known about the inheritance or genetic defect responsible.  Colobomas and polydactyly have been found in relatives of patients with Biemond syndrome suggesting that this may be an autosomal dominant disorder with variable penetrance.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

None known.

References
Article Title: 
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