teeth anomalies

Cleft Palate, Psychomotor Retardation, and Distinctive Facial Features

Clinical Characteristics
Ocular Features: 

The facial dysmorphism is present at birth together with the cleft palate.  Downslanting lid fissures, widely spaced eyes, and ptosis may be present.  Eyebrows have been described as sparse in one patient.  Strabismus and ocular apraxia are present in some children. 

Systemic Features: 

Three patients have been reported, one of whom also had a second deletion in a gene implicated in the Kabuki syndrome.  This individual had hypertrichosis and synophyrys whereas the others had sparse eyebrow and temporal hair.  The teeth are malformed with some conically shaped and widely spaced.  The forehead is prominent and the fingers are tapered and brachydactylous with 5th finger clinodactyly.

There are significant delays in achieving developmental milestones.  Hypotonia has been described.  Speech and walking in particular may be delayed for several years.   Physical growth may be delayed as well.  A variety of brain anomalies have been seen in some but not all individuals.  Hypospadius and cryptorchidism have been described.  All children reported have palatal anomalies.

Genetics

Heterozygous mutations in the KDM1A gene have been identified in two patients.  In another report a single patient had an out-of-frame 3-nucleotide deletion in the ANKRD11 gene (as sometimes found in Kabuki syndrome) plus a mutation in the KDM1A gene. 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

Gene discovery for Mendelian conditions via social networking: de novo variants in KDM1A cause developmental delay and distinctive facial features

Chong JX, Yu JH, Lorentzen P, Park KM, Jamal SM, Tabor HK, Rauch A, Saenz MS, Boltshauser E, Patterson KE, Nickerson DA, Bamshad MJ. Gene discovery for Mendelian conditions via social networking: de novo variants in KDM1A cause developmental delay and distinctive facial features. Genet Med. 2015 Dec 10. doi: 10.1038/gim.2015.161. [Epub ahead of print].

PubMed ID: 
26656649

Rothmund-Thomson Syndrome

Clinical Characteristics
Ocular Features: 

Patients have been reported with juvenile and infantile cataracts.  Reported prevalence varies possibly because the diagnostic criteria have not been established and more than one disorder may be represented by the title.  Rothmund (an ophthalmologist) originally reported two families of 5 children in which lens opacities were found, but Thomson, who was a dermatologist, in a later report did not mention cataracts.  The lens opacities are usually nuclear or posterior cortical in location and may be evident in 50% of patients.  Iris stromal changes such as hypoplasia have also been reported.  Eyelashes and/or eyebrows may be sparse.  This is likely the same disorder as the previously described ‘mesodermal dysgenesis of the iris and skeletal dysplasia’ and formerly listed as 270240 in OMIM.

Systemic Features: 

This is a clinically heterogeneous disorder.  Skin atrophy with pigmentary changes, telangiectasia, short stature, premature aging, and skeletal abnormalities are characteristic.  There is an increased risk of malignancy, particularly osteosarcomas and skin cancer.  Saddle nose, sparse hair, hypogonadism, dysplastic nails, and teeth anomalies have also been described.

The skin is usually normal at birth but an erythematous rash typically appears in the first six months of life accompanied by swelling and blistering.  Eventually areas of hypo- and hyperpigmentation appear in a reticulated pattern with spots of punctate atrophy and telangiectasia.  Hyperkeratosis of the soles of the feet is common.  The skeletal abnormalities of dysplasia, radial ray defects, and missing bones are often evident at birth while osteopenia and delayed bone maturation are evident later.

Genetics

This is an autosomal recessive disorder in which most patients have mutations in the RECQL4 gene (8q24.3).

Mutations in the same gene cause Baller-Gerold syndrome (218600) suggesting that the two disorders are allelic but the phenotypes are considerably different.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

There is no treatment for the primary disorder but patients must be monitored for malignancies.  Visually significant cataracts should be removed.  It has been recommended that patients avoid excessive sun exposure to reduce the risk of skin cancers.

References
Article Title: 
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