syndactyly

Sweeney-Cox Syndrome

Clinical Characteristics
Ocular Features: 

 Periorbital and facial anomalies were present in the two reported patients.  Pseudoproptosis (considered secondary to deficiency of the bony orbits) accentuated by midface hypoplasia, and upper lid colobomas have been observed.  The globes were described as "small" although there were no "concerns" regarding vision in the single male patient.  Electrodiagnostic tests were "normal."    

Systemic Features: 

Multiple anomalies and malformations were present in the two reported patients, an unrelated male and female.  Severe facial dysmorphism secondary to uneven skull bone formation and suture closures is present.  The metopic ridge is prominent, the orbital bones are deficient, the occiput is flattened, the anterior fontanel and coronal sutures are wide.  Midfacial hypoplasia is present.  The neck is broad and the shoulders are narrow.  The fingers are long and the distal phalanges may be fixed in flexion.  The ears are low-set, small, and cupped.  The palate is high and may be cleft.  Cutaneous syndactyly of the fingers has been observed.  Variable developmental delays/learning difficulties are present.

The male had an imperforate anus, undescended testes and a 60 dB hearing loss.  The female had a midline cleft palate with choanal atresia requiring a tracheostomy from birth and required fundoplication and gastrostomy for gastroesophageal reflux.

Genetics

Heterozygous missense mutations in the TWIST1 gene (7p21.1) were found in both reported individuals.  These appear to have arisen de novo.

Mutations in the same gene have also been found in the Saethre-Chotzen Syndrome (101400) in which some of the same skeletal features are found.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment has been reported for the general condition but individual malformations may require attention.  The lid colobomas were repaired in the female but corneal exposure remained and corneal scarring and phthisis developed in the right eye.  The left eye retained some vision ("able to see large objects").

References
Article Title: 

Localized TWIST1 and TWIST2 basic domain substitutions cause four distinct human diseases that can be modeled in Caenorhabditis elegans

Kim S, Twigg SRF, Scanlon VA, Chandra A, Hansen TJ, Alsubait A, Fenwick AL, McGowan SJ, Lord H, Lester T, Sweeney E, Weber A, Cox H, Wilkie AOM, Golden A, Corsi AK. Localized TWIST1 and TWIST2 basic domain substitutions cause four distinct human diseases that can be modeled in Caenorhabditis elegans. Hum Mol Genet. 2017 Jun 1;26(11):2118-2132.

PubMed ID: 
28369379

Diagnostic value of exome and whole genome sequencing in craniosynostosis

Miller KA, Twigg SR, McGowan SJ, Phipps JM, Fenwick AL, Johnson D, Wall SA, Noons P, Rees KE, Tidey EA, Craft J, Taylor J, Taylor JC, Goos JA, Swagemakers SM, Mathijssen IM, van der Spek PJ, Lord H, Lester T, Abid N, Cilliers D, Hurst JA, Morton JE, Sweeney E, Weber A, Wilson LC, Wilkie AO. Diagnostic value of exome and whole genome sequencing in craniosynostosis. J Med Genet. 2017 Apr;54(4):260-268.

PubMed ID: 
27884935

Sweeney-Cox Syndrome

Clinical Characteristics
Ocular Features: 

Ophthalmologic examinations have not been reported.  However, periorbital and facial anomalies were present in the two reported patients.  Pseudoproptosis (considered secondary to deficiency of the bony orbits) accentuated by midface hypoplasia, and upper lid colobomas have been observed.  The globes were described as "small" although there were no "concerns" regarding vision in the single male patient.  Electrodiagnostic tests were "normal."    

Systemic Features: 

Multiple anomalies and malformations were present in the two reported patients, an unrelated male and female.  Severe facial dysmorphism secondary to uneven skull bone formation and suture closures is present.  The metopic ridge is prominent, the orbital bones are deficient, the occiput is flattened, the anterior fontanel and coronal sutures are wide.  Midfacial hypoplasia is present.  The neck is broad and the shoulders are narrow.  The fingers are long and the distal phalanges may be fixed in flexion.  The ears are low-set, small, and cupped.  The palate is high and may be cleft.  Cutaneous syndactyly of the fingers has been observed.  Variable developmental delays/learning difficulties are present.

The male had an imperforate anus, undescended testes and a 60 dB hearing loss.  The female had a midline cleft palate with choanal atresia requiring a tracheostomy from birth and required fundoplication and gastrostomy for gastroesophageal reflux.  

Genetics

Heterozygous missense mutations in the TWIST1 gene (7p21.1) were found in both reported individuals.  These appear to have arisen de novo.

Mutations in the same gene have also been found in the Saethre-Chotzen Syndrome (101400) in which some of the same skeletal features are found.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment has been reported for the general condition but individual malformations may require attention.  The lid colobomas were repaired in the female but corneal exposure remained and corneal scarring and phthisis developed in the right eye.  The left eye retained some vision ("able to see large objects").

References
Article Title: 

Localized TWIST1 and TWIST2 basic domain substitutions cause four distinct human diseases that can be modeled in Caenorhabditis elegans

Kim S, Twigg SRF, Scanlon VA, Chandra A, Hansen TJ, Alsubait A, Fenwick AL, McGowan SJ, Lord H, Lester T, Sweeney E, Weber A, Cox H, Wilkie AOM, Golden A, Corsi AK. Localized TWIST1 and TWIST2 basic domain substitutions cause four distinct human diseases that can be modeled in Caenorhabditis elegans. Hum Mol Genet. 2017 Jun 1;26(11):2118-2132.

PubMed ID: 
28369379

Diagnostic value of exome and whole genome sequencing in craniosynostosis

Miller KA, Twigg SR, McGowan SJ, Phipps JM, Fenwick AL, Johnson D, Wall SA, Noons P, Rees KE, Tidey EA, Craft J, Taylor J, Taylor JC, Goos JA, Swagemakers SM, Mathijssen IM, van der Spek PJ, Lord H, Lester T, Abid N, Cilliers D, Hurst JA, Morton JE, Sweeney E, Weber A, Wilson LC, Wilkie AO. Diagnostic value of exome and whole genome sequencing in craniosynostosis. J Med Genet. 2017 Apr;54(4):260-268.

PubMed ID: 
27884935

Fraser Syndrome 2

Clinical Characteristics
Ocular Features: 

Cryptophthalmos, both unilateral and bilateral, is the ocular hallmark.  The lid margins may be fused.

Systemic Features: 

Multiple systemic malformations are usually present.  A small mouth, nasal dysplasia with hypoplastic alae nasi, and syndactyly may be seen.  Urogenital malformations such as renal dysgenesis or dysplasia, ambiguous genitalia, streak ovaries may be present.  Pulmonary hypoplasia and imperforate anus have been reported.

Genetics

Homozygous mutations in the FREM2 gene (13q13.3) have been identified in Fraser syndrome 2.  

See Fraser syndrome 1 (219000) for additional features that may be present in Fraser syndrome.

Fraser syndrome 3 (617667) results from homozygous mutations in GRIP1.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Fraser Syndrome 3

Clinical Characteristics
Ocular Features: 

Cryptophthalmos is always present.  The anterior chamber was described as 'abnormal' in several stillborn male fetuses.

Systemic Features: 

Low-set simple ears were noted in two stillborn fetuses.  Micrognathia and a broad and beaked nose with notched alae nasi were described together with a malformed and atretic larynx.  The fingers and toes may be short and cutaneous syndactyly may be present.  The position of the anus may be abnormal.  The lungs may have abnormal lobulation and appear hyperplastic and hyperechogenic.  The bladder and kidneys may be absent.

Genetics

Homozygous mutations in the GRIP1 gene (12q14.3) have been identified in this autosomal recessive condition.

Fraser syndrome 1 (219000) results from homozygous mutations in the FRAS1 gene.

Fraser syndrome 2 (617666) is caused by homozygous mutations in the FREM2 gene.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Mutations in GRIP1 cause Fraser syndrome

Vogel MJ, van Zon P, Brueton L, Gijzen M, van Tuil MC, Cox P, Schanze D, Kariminejad A, Ghaderi-Sohi S, Blair E, Zenker M, Scambler PJ, Ploos van Amstel HK, van Haelst MM. Mutations in GRIP1 cause Fraser syndrome. J Med Genet. 2012 Apr 17. [Epub ahead of print].

PubMed ID: 
22510445

Jackson-Weiss Syndrome

Clinical Characteristics
Ocular Features: 

The facial malformation such as the flattened midface with maxillary hypoplasia leads to shallow orbits with the result that the eyes appear proptotic.  Some but not all individuals have strabismus, usually exotropia.  Optic atrophy has not been reported. 

Systemic Features: 

Infants usually present at birth with skull deformities resembling some variant of acrocephalosyndactyly.  Some or all of the skull sutures may be fused.  In some individuals craniectomy is necessary while others have normal brain development.  Few patients have evidence of abnormal neurological development and psychometric testing reveals IQ's in the normal range.  The midface is flattened with sometimes severe maxillary hypoplasia.  No hand deformities are present. 

There may be cutaneous syndactyly of the second and third toes.  Variable tarsal fusion is often present. The great toe may be abnormally broad and deviated medially.  The first metatarsals and proximal phalanges of the great toes are generally broad.

The phenotype is highly variable and even among individuals in genetically more homogeneous populations such as the Old Order Amish the range of facial, skull, and digital anomalies include features found among all of the craniosynostosis syndromes except for Apert syndrome.

Genetics

Heterozygous mutations in the FGFR2 gene (10q26.13) are likely responsible for this autosomal dominant condition. 

Other forms of craniosynostosis in which mutations in FGFR2 have been found are: Beare-Stevenson Syndrome (123790), Crouzon Syndrome (123500), Pfeiffer Syndrome (101600), Apert Syndrome (101200), and Saethre-Chotzen Syndrome (101400).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no treatment beyond surgical correction of selected malformations. The risk of exposure keratitis requires constant vigilance and appropriate corneal lubrication.

References
Article Title: 

Neu-Laxova Syndrome 1

Clinical Characteristics
Ocular Features: 

The globes are prominent, an appearance that is exaggerated sometimes by absence of the eyelids or ectropion.  The lashes may be absent in other patients.  Cloudy corneas and cataracts have been described.

Systemic Features: 

This is a lethal dysplasia-malformation syndrome in which some infants are stillborn while others do not live beyond a few days.  The placenta is often small and the umbilical cord is short.  Decreased fetal movements and polyhydramnios are often noted.  Microcephaly can be striking at birth but there is overall intrauterine growth retardation.  The skin is ichthyotic and dysplastic containing excess fatty tissue beneath the epidermis.  Digits are often small and may be fused (syndactyly).  There is generalized edema with ‘puffiness’ of the hands and feet.  The lungs are frequently underdeveloped and cardiac defects such as septal openings, patent ductus arteriosus and transposition of great vessels are common.  Males often have cryptorchidism while females have a bifid uterus and renal dysgenesis has been reported.

The face is dysmorphic with prominent globes (in spite of microphthalmia), the ears are large and malformed, the forehead is sloping, the nose is flattened and the jaw is small.  Some infants have a cleft lip and palate while the mouth is round and gaping.  The neck is usually short.

Severe brain malformations such as lissencephaly, cerebellar hypoplasia, and dysgenesis/agenesis of the corpus callosum are frequently present.

Genetics

This is an autosomal recessive disorder secondary to mutations in the PHGDH gene (1p12).

This condition has some clinical overlap with Neu-Laxova syndrome 2 (616038) but the latter is less severe and is caused by a different mutation.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is available.

References
Article Title: 

Neu-laxova syndrome is a heterogeneous metabolic disorder caused by defects in enzymes of the L-serine biosynthesis pathway

Acuna-Hidalgo R, Schanze D, Kariminejad A, Nordgren A, Kariminejad MH, Conner P, Grigelioniene G, Nilsson D, Nordenskjold M, Wedell A, Freyer C, Wredenberg A, Wieczorek D, Gillessen-Kaesbach G, Kayserili H, Elcioglu N, Ghaderi-Sohi S, Goodarzi P, Setayesh H, van de Vorst M, Steehouwer M, Pfundt R, Krabichler B, Curry C, MacKenzie MG, Boycott KM, Gilissen C, Janecke AR, Hoischen A, Zenker M. Neu-laxova syndrome is a heterogeneous metabolic disorder caused by defects in enzymes of the L-serine biosynthesis pathway. Am J Hum Genet. 2014 Sep 4;95(3):285-93.

PubMed ID: 
25152457

Roberts Syndrome

Clinical Characteristics
Ocular Features: 

The eyes often appear prominent as the result of shallow orbits.  Hypertelorism and microphthalmia can be present.  The sclerae can have a bluish hue.   Cataracts and central corneal clouding plus scleralization and vascularization of the peripheral corneas are sometimes seen.  Lid colobomas and down-slanting palpebral fissures may be present.

Systemic Features: 

Failure of both membranous and long bones to grow properly lead to a variety of abnormalities such as craniosynostosis, hypomelia, syndactyly, oligodactyly, malar hypoplasia, short neck, micrognathia, and cleft lip and palate.  The long bones of the limbs may be underdeveloped or even absent.  Contractures of elbow, knee, and ankle joints are common as are digital anomalies.  Low birth weight and slow postnatal growth rates are usually result in short stature.  The hair is often sparse and light-colored. 

Mental development is impaired and some children are diagnosed to have mental retardation.  Cardiac defects are common.  Facial hemangiomas are often present as are septal defects and sometimes a patent ductus arteriosus.  External genitalia in both sexes appear enlarged.  The kidneys may be polycystic or horseshoe-shaped.

Genetics

This is an autosomal recessive condition caused by mutations in the ESCO2 gene (8p21.1).  Mutations in the same gene are also responsible for what some have called the SC phocomelia syndrome (269000) which has a similar but less severe phenotype.  Some consider the two disorders to be variants of the same condition and they are considered to be the same entity in this database.  The gene product is required for structural maintenance of centromeric cohesion during the cell cycle.  Microscopic anomalies of the centromeric region (puffing of the heterochromatic regions) are sometimes seen during cell division.

The Baller-Gerold syndrome (218600) has some phenotypic overlap with Roberts syndrome but is caused by mutations in a different gene (RECQL4).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Severely affected infants may be stillborn or die in infancy.  Other individuals live to adulthood.  There is no treatment for this condition beyond specific correction of individual anomalies.

References
Article Title: 

Orofaciodigital Syndrome, Type VI

Clinical Characteristics
Ocular Features: 

Hypertelorism and epicanthal folds have been described.  Some patients have nystagmus and strabismus. Ocular apraxia and difficulties in smooth visual pursuit may be present.   

Systemic Features: 

Polydactyly of the hands is a common feature.  The central metacarpal is often Y-shaped leading to ‘central polydactyly’.  The large toes may be bifid.  Cognitive deficits are common and some patients have been considered mentally retarded.  The ears are low-set and rotated posteriorly.  Some patients have a conductive hearing loss.  Oral anomalies may include a lobed tongue, lingual and sublingual hemartomas, micrognathia, clefting, and multiple buccoalveolar frenula.  Congenital heart anomalies, micropenis, and cryptorchidism have been reported.  Tachypnea and tachycardia have been noted.  Some patients have some degree of skeletal dysplasia and many individuals are short in stature.

The presence of cerebellar abnormalities such as hypoplasia (including absence) of the vermis may help to distinguish type VI from other forms of OFDS.  Hypothalamic dysfunction may be responsible for poor temperature regulation (hyperthermia). The ‘molar tooth sign’ seen on brain MRIs in Joubert syndrome (213300) is also present in OFDS VI. 

Genetics

This is a rare condition with limited family information.  Parents in one family were consanguineous, and multiple affected sibs in other families suggest this may be an autosomal recessive condition.  Homozygous mutations in TMEM216 have been found. Other patients have mutations in C5orf42.

Many of the clinical features in OFDS VI are also found among individuals with Joubert (213300) and Meckel (249000) syndromes that also sometimes have mutations in the TMEM216 and C5orf42 genes.  Some consider all of these conditions to be members of a group of overlapping disorders called ciliopathies or ciliary dyskinesias.   

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No specific treatment is available for this syndrome but individual signs and symptoms may need treatment.

References
Article Title: 

C5orf42 is the major gene responsible for OFD syndrome type VI

Lopez E, Thauvin-Robinet C, Reversade B, Khartoufi NE, Devisme L, Holder M, Ansart-Franquet H, Avila M, Lacombe D, Kleinfinger P, Kaori I, Takanashi JI, Le Merrer M, Martinovic J, No?'l C, Shboul M, Ho L, G?oven Y, Razavi F, Burglen L, Gigot N, Darmency-Stamboul V, Thevenon J, Aral B, Kayserili H, Huet F, Lyonnet S, Le Caignec C, Franco B, Rivi?(r)re JB, Faivre L, Atti?(c)-Bitach T. C5orf42 is the major gene responsible for OFD syndrome type VI. Hum Genet. 2013 Nov 1. [Epub ahead of print].

PubMed ID: 
24178751

Mutations in TMEM216 perturb ciliogenesis and cause Joubert, Meckel and related syndromes

Valente EM, Logan CV, Mougou-Zerelli S, Lee JH, Silhavy JL, Brancati F, Iannicelli M, Travaglini L, Romani S, Illi B, Adams M, Szymanska K, Mazzotta A, Lee JE, Tolentino JC, Swistun D, Salpietro CD, Fede C, Gabriel S, Russ C, Cibulskis K, Sougnez C, Hildebrandt F, Otto EA, Held S, Diplas BH, Davis EE, Mikula M, Strom CM, Ben-Zeev B, Lev D, Sagie TL, Michelson M, Yaron Y, Krause A, Boltshauser E, Elkhartoufi N, Roume J, Shalev S, Munnich A, Saunier S, Inglehearn C, Saad A, Alkindy A, Thomas S, Vekemans M, Dallapiccola B, Katsanis N, Johnson CA, Atti?(c)-Bitach T, Gleeson JG. Mutations in TMEM216 perturb ciliogenesis and cause Joubert, Meckel and related syndromes. Nat Genet. 2010 Jul;42(7):619-25.

PubMed ID: 
20512146

Microphthalmia, Syndromic 6

Clinical Characteristics
Ocular Features: 

Ultrasound evaluation reveals globe size to vary widely from extremely small (6 mm) to normal axial length. Clinical anophthalmia is often diagnosed.  Both anophthalmia and microphthalmia may exist in the same individual. True anophthalmia has been confirmed in some patients in which no ocular tissue was detectable with ultrasound examination.  In such cases the optic nerves and chiasm are often missing as well.  Iris colobomas are common and these may extend posteriorly.  Myopia is sometimes present.

The ERG reveals generalized rod and cone dysfunction in some eyes, but may be normal in others. In many eyes the ERG is nonrecordable. Cataracts are frequently present.

Systemic Features: 

Digital and hand anomalies are common.  The hands are often described as broad and the thumbs may be low-placed.  The nails can appear dysplastic and postaxial polydactyly is often present.  Mild webbing of the fingers has been reported as well.  Microcephaly and the cranium can be misshapen. A high arched palate is often present and clefting has also been noted.  Micrognathia may be present. Some evidence of physical growth retardation is often evident.

Pituitary hypoplasia is not uncommon and may be associated with hypothyroidism and cryptorchidism with hypospadias, and a small or bifid scrotum.

The brain anomalies vary considerably.  Many patients have mild to moderate developmental delays with some learning difficulties. Sensorineural hearing loss is often present. Hypoplasia of the vermis, thinning of the corpus callosum, widening of the lateral ventricles, and occasional generalized cortical atrophy, at least in older individuals, have been described.

Genetics

This is an autosomal dominant condition caused by a point mutation in BMP4 (bone morphogenetic protein-4) (14q22-q23).  A number of chromosomal deletions involving this gene have also been identified in individuals who have this syndrome but since contiguous genes such as OTX2 and SIX6 may also be involved, the phenotype is more likely to be associated with other anomalies including genital hypoplasia, pituitary hypoplasia, absence of the optic nerves and/or chiasm, developmental delay, digital malformations, and cerebellar dysplasia.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Cataracts can be removed in selected individuals with potential visual function.  Socket prostheses should be considered in anophthalmia and extreme microphthalmia.  Low vision devices, Braille, and mobility training should be initiated early when appropriate.  Hearing evaluations should be done as soon as practical.

Learning specialists and special education facilities should be available for selected patients.  Polydactyly, syndactyly, skull, and cleft palate repairs may be indicated.

References
Article Title: 

Mutations in BMP4 cause eye, brain, and digit developmental anomalies: overlap between the BMP4 and hedgehog signaling pathways

Bakrania P, Efthymiou M, Klein JC, Salt A, Bunyan DJ, Wyatt A, Ponting CP, Martin A, Williams S, Lindley V, Gilmore J, Restori M, Robson AG, Neveu MM, Holder GE, Collin JR, Robinson DO, Farndon P, Johansen-Berg H, Gerrelli D, Ragge NK. Mutations in BMP4 cause eye, brain, and digit developmental anomalies: overlap between the BMP4 and hedgehog signaling pathways. Am J Hum Genet. 2008 Feb;82(2):304-19.

PubMed ID: 
18252212

Feingold Syndrome 1

Clinical Characteristics
Ocular Features: 

Short, narrow palpebral fissures have been reported (73%).  The fissures may be up slanting and epicanthal folds have been noted.   

Systemic Features: 

The face can appear asymmetrical and triangular and the head is small in 89% of individuals.  Micrognathia is usually present and the lips appear full.  The nasal bridge is broad and the nostrils are anteverted.  The ears are often low-set and rotated posteriorly.  Syndactyly of the toes is common (97%) and the fingers are often anomalous (particularly 5th finger clinodactyly and brachydactyly) with hypoplastic thumbs.  Shortening of the 2nd and 5th middle phalanx of the fingers is especially common.  True short stature is uncommon but 60% are below the 10th centile.  Rare individuals have a sensorineural hearing loss.

Tracheoesophageal fistulas are often present, together with atresia of the duodenum and sometimes the esophagus as well.  Cardiac, renal, and vertebral malformations are seen in a minority of patients.

Intelligence may be normal but more often is below average and learning difficulties are often present.

Genetics

This is an autosomal dominant disorder secondary to mutations in the MYCN gene (2p24.3).

MYCN is up regulated in some patients with retinoblastoma (180200).

Feingold syndrome 2 (614326) is caused by hemizygous deletions of the MIR17HG gene but no ocular signs have been reported.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no known treatment for the syndrome but surgery can be important for some of the external and internal malformations. Special education and treatment of hearing loss are important.

References
Article Title: 

Genotype-phenotype correlations in MYCN-related Feingold syndrome

Marcelis CL, Hol FA, Graham GE, Rieu PN, Kellermayer R, Meijer RP, Lugtenberg D, Scheffer H, van Bokhoven H, Brunner HG, de Brouwer AP. Genotype-phenotype correlations in MYCN-related Feingold syndrome. Hum Mutat. 2008 Sep;29(9):1125-32.

PubMed ID: 
18470948

Pages

Subscribe to RSS - syndactyly