retrognathia

Carey-Fineman-Ziter Syndrome

Clinical Characteristics
Ocular Features: 

Abnormal eye movements with prominent external ophthalmoplegia are hallmarks of this disease.  An oculomotor nerve palsy with limited abduction and some degree of facial palsy are usually present.  The Moebius sequence is present in many patients.  Epicanthal folds, downslanting lid fissures, and ptosis are frequently seen.

Systemic Features: 

Clinical signs are highly variable.  Unusual facies with features of the Pierre Robin complex are characteristic.  Micrognathia and retrognathia are often present with glossoptosis.  Hypotonia and failure to thrive are commonly seen.  Dysphagia and even absent swallowing likely contribute to this.  Respiratory insufficiency can be present from birth, often with laryngostenosis, and some patients develop pulmonary hypertension and restrictive lung disease as adults.  Progressive scoliosis may contribute to this.  Many patients have club feet with joint contractures.  Skull formation consisting of microcephaly, or macrocephaly, or plagiocephaly is commonly seen.  Cardiac septal defects are common.

Intellectual disability is present in some but not all individuals.  Neuronal heterotopias, enlarged ventricles, reduced white matter, a small brainstem, microcalcifications, and enlarged ventricles have been observed.

Genetics

Homozygous or compound heterozygosity of the MYMK gene (9q34) is responsible for this condition.  

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment for the general disorder has been reported.

References
Article Title: 

A defect in myoblast fusion underlies Carey-Fineman-Ziter syndrome

Di Gioia SA, Connors S, Matsunami N, Cannavino J, Rose MF, Gilette NM, Artoni P, de Macena Sobreira NL, Chan WM, Webb BD, Robson CD, Cheng L, Van Ryzin C, Ramirez-Martinez A, Mohassel P, Leppert M, Scholand MB, Grunseich C, Ferreira CR, Hartman T, Hayes IM, Morgan T, Markie DM, Fagiolini M, Swift A, Chines PS, Speck-Martins CE, Collins FS, Jabs EW, Bonnemann CG, Olson EN; Moebius Syndrome Research Consortium, Carey JC, Robertson SP, Manoli I, Engle EC. A defect in myoblast fusion underlies Carey-Fineman-Ziter syndrome. Nat Commun. 2017 Jul 6;8:16077. doi: 10.1038/ncomms16077.

PubMed ID: 
28681861

Möbius sequence, Robin complex, and hypotonia: severe expression of brainstem disruption spectrum versus Carey-Fineman-Ziter syndrome

Verloes A, Bitoun P, Heuskin A, Amrom D, van de Broeck H, Nikkel SM, Chudley AE, Prasad AN, Rusu C, Covic M, Toutain A, Moraine C, Parisi MA, Patton M, Martin JJ, Van Thienen MN. Mobius sequence, Robin complex, and hypotonia: severe expression of brainstem disruption spectrum versus Carey-Fineman-Ziter syndrome. Am J Med Genet A. 2004 Jun 15;127A(3):277-87.

PubMed ID: 
15150779

Marfan Lipodystrophy Syndrome

Clinical Characteristics
Ocular Features: 

The eyes are large resulting in high myopia and apparent proptosis.  The palpebral fissures usually slant downwards and ectopia lentis may be present.  

Systemic Features: 

This syndrome shares many features of Marfan syndrome (154700) such as tall stature, dislocated lenses, myopia, high arched palate, aortic root and valvular anomalies, arachnodactyly, high arched palate, lax and hyperextensible joints, and pectus excavatum.  In addition, MFLS patients have retrognathia, intrauterine growth retardation, scarce or absent subcutaneous fat, a progeroid facies, and sometimes macrocephaly.  Postnatal growth and psychomotor development have been reported to be normal albeit with slow weight gain.

Genetics

This condition is transmitted as an autosomal dominant as the result of heterozygous mutations in FBN1 (15q21.1).  The same gene is mutated in 6 other conditions in this database including Marfan Syndrome (154700) with which it shares some features.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

There is no treatment for the overall condition but individual features such as ectopia lentis can be surgically corrected.  Patients with high myopia require frequent evaluation for retinal tears and detachments.  Cardiac monitoring likewise is important to monitor for aortic valve prolapse and dilation of the aortic root.

References
Article Title: 

Cerebellar Atrophy, Visual Impairment, and Psychomotor Retardation

Clinical Characteristics
Ocular Features: 

Patients usually have deep-set eyes.  Cortical visual impairment has been described in one patient but optic atrophy has been seen in another.  The VEP and ERG are described as 'abnormal'.  Strabismus, hyperopia, and myopia are sometimes seen.

Systemic Features: 

Progressive microcephaly is often noted.  Truncal hypotonia and scoliosis may be present while muscle tone is increased in the extremities in the presence of diminished deep tendon reflexes in other patients.  Dystonic posturing occurs in some families.  Gingival hyperplasia is a common feature and retrognathia is often present.

Brain imaging reveals progressive cerebellar atrophy and a foreshortened corpus callosum in all families.  Various degrees of cerebral atrophy have been identified while intellectual disability may be marked.  Speech delay is common.

Genetics

This is an autosomal recessive condition associated with homozygous mutations in the EMC1 gene (1p36.13).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatnent has been reported.

References
Article Title: 

Monoallelic and Biallelic Variants in EMC1 Identified in Individuals with Global Developmental Delay, Hypotonia, Scoliosis, and Cerebellar Atrophy

Harel T, Yesil G, Bayram Y, Coban-Akdemir Z, Charng WL, Karaca E, Al Asmari A, Eldomery MK, Hunter JV, Jhangiani SN, Rosenfeld JA, Pehlivan D, El-Hattab AW, Saleh MA, LeDuc CA, Muzny D, Boerwinkle E; Baylor-Hopkins Center for Mendelian Genomics, Gibbs RA, Chung WK, Yang Y, Belmont JW, Lupski JR. Monoallelic and Biallelic Variants in EMC1 Identified in Individuals with Global Developmental Delay, Hypotonia, Scoliosis, and Cerebellar Atrophy. Am J Hum Genet. 2016 Mar 3;98(3):562-70.

PubMed ID: 
26942288

Cole-Carpenter Syndrome 2

Clinical Characteristics
Ocular Features: 

Postnatally the eyes are prominent and hypertelorism has been reported.  The palpebral fissures slant downward and the root of the nose is angular. 

Systemic Features: 

This is primarily a skeletal disorder with impaired skull ossification and multiple bone fractures of prenatal origin.  It is sometimes confused with forms of osteogenesis imperfecta.  The skull is poorly ossified and frequent diaphyseal fractures of the long bones occur leading to motor delays and short stature.  Rib fractures are sometimes seen. Intelligence seems to be normal.  A receding chin has been noted and the hard palate is highly vaulted.  The midface is flat.

Genetics

This disorder results from compound heterozygous mutations in the SEC24D gene (4q26).  Only a few patients have been reported.

For a somewhat similar but autosomal dominant disorder see Cole-Carpenter Syndrome 1 (112240).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Physical activity should be restricted to noncontact sports and where the cranium has ossification defects a helmet should be worn.  Fractures should be appropriately treated.

References
Article Title: 

Mutations in SEC24D, Encoding a Component of the COPII Machinery, Cause a Syndromic Form of Osteogenesis Imperfecta

Garbes L, Kim K, Riess A, Hoyer-Kuhn H, Beleggia F, Bevot A, Kim MJ, Huh YH, Kweon HS, Savarirayan R, Amor D, Kakadia PM, Lindig T, Kagan KO, Becker J, Boyadjiev SA, Wollnik B, Semler O, Bohlander SK, Kim J, Netzer C. Mutations in SEC24D, Encoding a Component of the COPII Machinery, Cause a Syndromic Form of Osteogenesis Imperfecta. Am J Hum Genet. 2015 Mar 5;96(3):432-9.

PubMed ID: 
25683121

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
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