broad nasal bridge

Elsahy-Waters Syndrome

Clinical Characteristics
Ocular Features: 

Structural anomalies of periocular tissues are common.  Hypertelorism, proptosis, and telecanthus may be striking.  Colobomas or clefts of the upper lid are frequently seen.  The eyebrows are bushy and synophyrs may be present across a broad nasal bridge.  Megalocornea, downslanting lid fissures, glaucoma and cataracts have also been reported but are uncommon.

Systemic Features: 

The skull has been described as brachycephalic.  The midface is flat due to maxillary hypoplasia. The lower jaw is prominent and some patients have mandibular prognathism.  A bifid uvula or partial clefting of the palate are common.  Low-set and posteriorly rotated ears have been reported as well.

 Both pectus excavatum and pectus carinatum have been described.  The teeth have dysplastic enamel and often have obliterated pulp chambers and dental cysts.  Their roots may be shortened and deformed and they are often lost early.  Vertebrae may have fusion of the spines, particularly in the cervical area.  A mixed type of hearing loss is common and some degree of intellectual disability is often evident, especially in older individuals.  Most males have some degree of hypospadias.  Cryptorchidism has been reported in one individual.

Brain imaging in one case revealed no abnormalities.

Genetics

This disorder results from biallelic mutations in the CDH11 gene (16q21).  The parents have been consanguineous in most reports and no vertical transmission has been documented making autosomal recessive the most likely pattern of inheritance.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment for the general disorder has been reported.  Eyelid and palatal defects may be surgically repaired and assistive hearing devices may be of benefit.  Special education is also likely to be helpful.

References
Article Title: 

Rubinstein-Taybi Syndrome 2

Clinical Characteristics
Ocular Features: 

Highly-arched and bushy eyebrows are often seen.  The lashes are long and bushy and lid fissures tend to slope downward.

The ocular phenotype has not been fully described no doubt due to the rarity of cases.  Individuals with type 1 (RSTS1) have been described with congenital glaucoma, nystagmus, corneal abnormalities of shape (such as keratoglobus, sclerocornea, megalocornea), pigmentary retinopathy, and VEP evidence of rod and cone dysfunction have been described.

Systemic Features: 

The phenotype of RSTS2 is more variable than the somewhat similar RSTS1.  Less than 10% of individuals with Rubinstein-Taybi syndrome have type 2 while over 50% have type 1.  The facial dysmorphism nay be less severe in RSTS2.

Mild to moderate intellectual disability with psychosocial problems such as autism is nearly universal.  Microcephaly, a broad nasal bridge, a beaked nose, high-arched palate and some degree of micrognathia are characteristic.  The lower lip often appears 'pouty' and protrudes beyond the upper lip while the hard palate is highly arched.  Pregnancy may be complicated by pre-eclampsia and growth restriction.  Swallowing and feeding issues are common.  Syndactyly is often present and there is considerable variability in the size of the toes and thumbs.  Some patients with RSTS2 do not have evidence of the classic broad thumbs and toes characteristic of RSTS1.

Genetics

Heterozygous mutations in EP300 (22q13.2) have been found in this condition.  Virtually all cases occur de novo.  Rubinstein-Taybi Syndrome 1 (180849) is a phenotypically similar disorder resulting from a different mutation (CREBBP).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no treatment for this condition.

References
Article Title: 

Mental Retardation, X-Linked 99, Syndromic, Female-Restricted

Clinical Characteristics
Ocular Features: 

Palpebral fissures are generally shortened and may slant up or down.  Cataracts of unknown morphology have been reported and strabismus is common.

Systemic Features: 

The systemic phenotype is highly variable.  Skull and facial anomalies are common with brachycephaly, bitemporal narrowing, and a broad low nasal bridge. There is general developmental delay in both motor and cognitive abilities.  Patients are short in stature while scoliosis, hip dysplasia, and post-axial polydactyly may be present.  The teeth may be malformed and numerous (29%) of individuals have hypertrichosis.  Nearly a third of individuals have a cleft palate/bifid uvula.   Heart malformations, primarily atrial septal defects, are found in about half of affected individuals and urogenital anomalies such as renal dysplasia are relatively common.  Feeding difficulties have been reported while anal atresia is present in about half of patients.   

Brain imaging reveals hypoplasia of the corpus callosum, enlarged ventricles, Dandy-Walker malformations, cerebellar hypoplasia, and abnormal gyration patterns in the frontal lobe.  Generalized hypotonia has been diagnosed in half of reported patients and seizures occur in 24%.

Genetics

This female-restricted syndrome is caused by heterozygous mutations in the USP9X gene (Xp11.4).  X-chromosome inactivation is skewed greater than 90% in the majority of females but the degree of skewing in one study was independent of clinical severity.  The majority of cases occur de novo.

In males, hemizygous mutations in the USP9X gene (300919) cause a somewhat similar disorder (MRX99) without the majority of the congenital malformations having mainly the intellectual disabilities, hypotonia, and behavioral problems.

Pedigree: 
X-linked dominant, mother affected
Treatment
Treatment Options: 

There is no known treatment for the general disorder but individual anomalies or defects such as atrial septal defects, cleft palate, and anal atresia might be surgically corrected.

References
Article Title: 

De Novo Loss-of-Function Mutations in USP9X Cause a Female-Specific Recognizable Syndrome with Developmental Delay and Congenital Malformations

Reijnders MR, Zachariadis V, Latour B, Jolly L, Mancini GM, Pfundt R, Wu KM, van Ravenswaaij-Arts CM, Veenstra-Knol HE, Anderlid BM, Wood SA, Cheung SW, Barnicoat A, Probst F, Magoulas P, Brooks AS, Malmgren H, Harila-Saari A, Marcelis CM, Vreeburg M, Hobson E, Sutton VR, Stark Z, Vogt J, Cooper N, Lim JY, Price S, Lai AH, Domingo D, Reversade B; DDD Study, Gecz J, Gilissen C, Brunner HG, Kini U, Roepman R, Nordgren A, Kleefstra T. De Novo Loss-of-Function Mutations in USP9X Cause a Female-Specific Recognizable Syndrome with Developmental Delay and Congenital Malformations. Am J Hum Genet. 2016 Feb 4;98(2):373-81.

PubMed ID: 
26833328

Filippi Syndrome

Clinical Characteristics
Ocular Features: 

The ocular features have not been fully described.  The most consistent features are long eyelashes, thick (bushy) eyebrows, and 'visual disturbance'.  Most individuals have a facial dysmorphism which includes a broad nasal base suggestive of hypertelorism.  Optic atrophy and proptosis have been noted. 

Systemic Features: 

Intrauterine growth retardation is sometimes seen.  Microcephaly, short stature, syndactyly, intellectual disability (often labeled mental retardation), and a dysmorphic face are characteristic.  Some individuals have cryptorchidism, seizures, and ectodermal abnormalities including nail hypoplasia, hirsutism, and microdontia.  Mental and physical delays are common.  The syndactyly usually involves only soft tissue between toes 2, 3, and 4 and fingers 3 and 4 accompanied by clinodactyly of the 5th finger.  Polydactyly is sometimes present while radiologically the radial head may show evidence of hypoplasia. 

Genetics

Homozygosity or compound heterozygosity in the CKAP2L gene (2q13) segregates with this phenotype. 

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

Mutations in CKAP2L, the human homolog of the mouse Radmis gene, cause Filippi syndrome

Hussain MS, Battaglia A, Szczepanski S, Kaygusuz E, Toliat MR, Sakakibara S, Altmuller J, Thiele H, Nurnberg G, Moosa S, Yigit G, Beleggia F, Tinschert S, Clayton-Smith J, Vasudevan P, Urquhart JE, Donnai D, Fryer A, Percin F, Brancati F, Dobbie A, Smigiel R, Gillessen-Kaesbach G, Wollnik B, Noegel AA, Newman WG, Nurnberg P. Mutations in CKAP2L, the human homolog of the mouse Radmis gene, cause Filippi syndrome. Am J Hum Genet. 2014 Nov 6;95(5):622-32.

PubMed ID: 
25439729

Coloboma, Ptosis, Hypertelorism, and Global Delay

Clinical Characteristics
Ocular Features: 

The ocular phenotype includes ptosis, hypertelorism, iris coloboma and prominent epicanthal folds with epicanthus inversus.  The coloboma may be unilateral and involve other portions of the uveal tract. The orbits have been described as shallow.  At least one patient has been described as having microphthalmia and microcornea.

Systemic Features: 

The systemic features reported include severe global delay, a broad nasal bridge, and short stature.  Physical growth delay, mental retardation, short neck, low-set ears, and low posterior hairline have been noted.  Males may have a micropenis and undescended testicles.  The pinnae may be malformed and rotated posteriorly. Several patients had a hearing deficit.

CT scans have shown microcephaly with pachygyria and or even virtual agyria of the frontal, temporal, and parietal lobes.

Genetics

This condition is caused by heterozygous mutations in the ACTG1 gene (17q25.3) and therefore transmitted in an autosomal dominant pattern.  Sibs but no parental consanguinity has been reported.  Both sexes are affected.

Mutations in the same gene are responsible for a somewhat similar condition known as Baraister-Winter 2 syndrome (614583).

Temtamy syndrome (218340) has some similar features but is caused by mutations in C12orf57 (12p13).  In addition to microphthalmia and colobomas, intractable seizures, global delay and abnormalities of the corpus callosum are present.

Several patients that may have had this syndrome have had pericentric inversions of chromosome 2: inv(2)(p12q14).  The PAX8 gene maps to the distal breakpoint of this inversion and may play a role as the location of a recessive mutation or as part of a submicroscopic inversion.  No parent-child transmission has been reported.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

Exome sequencing identifies compound heterozygous mutations in C12orf57 in two siblings with severe intellectual disability, hypoplasia of the corpus callosum, chorioretinal coloboma, and intractable seizures

Platzer K, Huning I, Obieglo C, Schwarzmayr T, Gabriel R, Strom TM, Gillessen-Kaesbach G, Kaiser FJ. Exome sequencing identifies compound heterozygous mutations in C12orf57 in two siblings with severe intellectual disability, hypoplasia of the corpus callosum, chorioretinal coloboma, and intractable seizures. Am J Med Genet A. 2014 May 5. [Epub ahead of print].

PubMed ID: 
24798461
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