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A temporal-bone CT using thin slices makes it possible to diagnose the degree of stenosis and atresia of the external auditory canal, the status of the middle ear cavity, the absent or dysplastic and rudimentary ossicles, or inner ear abnormalities such as a deficient cochlea. Two- and three-dimensional CT reconstructions with VRT and bone and skin-surfacing are helpful for more accurate staging and the three-dimensional planning of mandibular and external ear reconstructive surgery.
A few techniques are used to confirm the diagnosis in TCS.
An orthopantomogram (OPG) is a panoramic dental X-ray of the upper and lower jaw. It shows a two-dimensional image from ear to ear. Particularly, OPG facilitates an accurate postoperative follow-up and monitoring of bone growth under a mono- or double-distractor treatment. Thereby, some TCS features could be seen on OPG, but better techniques are used to include the whole spectrum of TCS abnormalities instead of showing only the jaw abnormalities.
Another method of radiographic evaluation is taking an X-ray image of the whole head. The lateral cephalometric radiograph in TCS shows hypoplasia of the facial bones, like the malar bone, mandible, and the mastoid.
Finally, occipitomental radiographs are used to detect hypoplasia or discontinuity of the zygomatic arch.
Suspicion of a chromosome abnormality is typically raised due to the presence of developmental delays or birth defects. Diagnosis of distal 18q- is usually made from a blood sample. A routine chromosome analysis, or karyotype, is usually used to make the initial diagnosis, although it may also be made by microarray analysis. Increasingly, microarray analysis is also being used to clarify breakpoints. Prenatal diagnosis is possible using amniocentesis or chorionic villus sampling.
At present, treatment for distal 18q- is symptomatic, meaning the focus is on treating the signs and symptoms of the conditions as they arise. To ensure early diagnosis and treatment, people with distal 18q- are suggested to undergo routine screenings for thyroid, hearing, and vision problems.
A clinical diagnosis of SCS can be verified by testing the TWIST1 gene (only gene in which mutations are known to cause SCS) for mutations using DNA analysis, such as sequence analysis, deletion/duplication analysis, and cytogenetics/ FISH analysis. Sequence analysis of exon 1 (TWIST1 coding region) provides a good method for detecting the frequency of mutations in the TWIST1 gene. These mutations include nonsense, missense, splice site mutation, and intragenic deletions/insertions. Deletion/duplication analysis identifies mutations in the TWIST1 gene that are not readily detected by sequence analysis. Common methods include PCR, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray (CMA). Cytogenetic/FISH analysis attaches fluorescently labels DNA markers to a denatured chromosome and is then examined under fluorescent lighting, which reveals mutations caused by translocations or inversions involving 7p21. Occasionally, individuals with SCS have a chromosome translocation, inversion, or ring chromosome 7 involving 7p21 resulting in atypical findings, such as, increased developmental delay. Individuals with SCS, typically have normal brain functioning and rarely have mental impairments. For this reason, if an individual has both SCS and mental retardation, then they should have their TWIST1 gene screened more carefully because this is not a normal trait of SCS. Cytogenetic testing and direct gene testing can also be used to study gene/chromosome defects. Cytogenetic testing is the study of chromosomes to detect gains or losses of chromosomes or chromosome segments using fluorescent in situ hybridization (FISH) and/or comparative genomic hybridization (CGH). Direct gene testing uses blood, hair, skin, amniotic fluid, or other tissues in order to find genetic disorders. Direct gene testing can determine whether an individual has SCS by testing the individual's blood for mutations in the TWIST1 gene.
Carrier testing for Roberts syndrome requires prior identification of the disease-causing mutation in the family. Carriers for the disorder are heterozygotes due to the autosomal recessive nature of the disease. Carriers are also not at risk for contracting Roberts syndrome themselves. A prenatal diagnosis of Roberts syndrome requires an ultrasound examination paired with cytogenetic testing or prior identification of the disease-causing ESCO2 mutations in the family.
The constellation of anomalies seen with Nasodigitoacoustic syndrome result in a distinct diagnosis. The diagnostic criteria for the disorder are broad distal phalanges of the thumbs and big toes, accompanied by a broad and shortened nose, sensorineural hearing loss and developmental delay, with predominant occurrence in males.
Up until recently, experts frequently disagreed on whether a patient had SCS, Crouzon syndrome, isolated craniosynostosis, or some other disease because the symptoms are so closely related, they literally had no way of differentiating between all of them. However, we now have direct gene testing, which allows for a more definitive diagnosis because it allows them to be differentiated from each other based on which gene is mutated in each condition. The following is a list of conditions commonly confused/misdiagnosed for SCS, some of their symptoms, and which mutated gene each contains:
Nasodigitoacoustic syndrome is similar to several syndromes that share its features. Brachydactyly of the distal phalanges, sensorineural deafness and pulmonary stenosis are common with Keutel syndrome. In Muenke syndrome, developmental delay, distal brachydactyly and sensorineural hearing loss are reported; features of Teunissen-Cremers syndrome include nasal aberrations and broadness of the thumbs and big toes, also with brachydactyly. Broad thumbs and big toes are primary characteristics of Rubinstein syndrome.
Weissenbacher-Zweymüller syndrome is diagnosed upon a thorough clinical evaluation, detailed patient history, identification of characteristic symptom and a variety of specialized tests which includes x-rays.
13q deletion syndrome can only be definitively diagnosed by genetic analysis, which can be done prenatally or after birth. Increased nuchal translucency in a first-trimester ultrasound may indicate the presence of 13q deletion.
Many professionals that are likely to be involved in the treatment of those with Stickler's syndrome, include anesthesiologists, oral and maxillofacial surgeons; craniofacial surgeons; ear, nose, and throat specialists, ophthalmologists, optometrists, audiologists, speech pathologists, physical therapists and rheumatologists.
Cytogenetic preparations that have been stained by either Giemsa or C-banding techniques will show two characteristic chromosomal abnormalities. The first chromosomal abnormality is called premature centromere separation (PCS) and is the most likely pathogenic mechanism for Roberts syndrome. Chromosomes that have PCS will have their centromeres separate during metaphase rather than anaphase (one phase earlier than normal chromosomes). The second chromosomal abnormality is called heterochromatin repulsion (HR). Chromosomes that have HR experience separation of the heterochromatic regions during metaphase. Chromosomes with these two abnormalities will display a "railroad track" appearance because of the absence of primary constriction and repulsion at the heterochromatic regions. The heterochromatic regions are the areas near the centromeres and nucleolar organizers. Carrier status cannot be determined by cytogenetic testing. Other common findings of cytogenetic testing on Roberts syndrome patients are listed below.
- Aneuploidy- the occurrence of one or more extra or missing chromosomes
- Micronucleation- nucleus is smaller than normal
- Multilobulated Nuclei- the nucleus has more than one lobe
Imaging is usually not pursued in those with uncomplicated conductive hearing loss and characteristic clinical findings. Those with only conductive hearing loss are often treated medically or with surgery without imaging. The diagnosis may be unclear clinically in cases of sensorineural or mixed hearing loss and may become apparent only on imaging. Therefore, imaging is often performed when the hearing loss is sensorineural or mixed.
A high-resolution CT shows very subtle bone findings. However, CT is usually not needed prior to surgery.
Otosclerosis on CT can be graded using the grading system suggested by Symons and Fanning.
- Grade 1, solely fenestral;
- Grade 2, patchy localized cochlear disease (with or without fenestral involvement) to either the basal cochlear turn (grade 2A), or the middle/apical turns (grade 2B), or both the basal turn and the middle/apical turns (grade 2C); and
- Grade 3, diffuse confluent cochlear involvement (with or without fenestral involvement).
Diagnosis of otodental syndrome was established using clinical, histopathological and audiometric methodologies. In normal individuals, by the age of 2-3, radiograph images should depict any signs of premolar development. A formal diagnosis of no premolar growth can be done by age 6 in order to check for signs of otodental syndrome. Sensorineural hearing loss can be another measure for proper diagnosis as well as checking for ocular coloboma. The latter is usually noticed at an around birth.
Molecular genetic testing can aid in the diagnosis of the affected individual, which would determine if there are any abnormalities in the FGF3 gene (11q13) or the FADD gene (11q13.3). Additional tests that can help diagnose otodental syndrome are ear infection tests, hearing tests, oral examination, and eye examinations to check for the specific phenotypic associations. Due to the rarity of otodental syndrome, most symptoms are looked at on an individual basis unless multiple symptoms are all apparent at once.
There is potential for differential diagnosis due to similarities in symptoms. Other diseases that share common symptoms are chondroectodermal dysplasia, achondrodysplasia, and osteopetrosis
Diagnosis is made based on features as well as by the very early onset of serious eye and ear disease. Because Marshall syndrome is an autosomal dominant hereditary disease, physicians can also note the characteristic appearance of the biological parent of the child. There are no tests for Stickler syndrome or Marshall syndrome. Some families with Stickler syndrome have been shown to have mutations in the Type II collagen gene on chromosome 1. However, other families do not show the linkage to the collagen gene. It is an area of active research, also the genetic testing being expensive supports that the diagnosis is made depending on the features.
This includes Ataxia-telegiectasia, Chédiak-Higashi syndrome, DiGeorge syndrome, Griscelli syndrome and Marinesco-Sjogren syndrome.
The main diagnostic tools for evaluating FND are X-rays and CT-scans of the skull. These tools could display any possible intracranial pathology in FND. For example, CT can be used to reveal widening of nasal bones. Diagnostics are mainly used before reconstructive surgery, for proper planning and preparation.
Prenatally, various features of FND (such as hypertelorism) can be recognized using ultrasound techniques. However, only three cases of FND have been diagnosed based on a prenatal ultrasound.
Other conditions may also show symptoms of FND. For example, there are other syndromes that also represent with hypertelorism. Furthermore, disorders like an intracranial cyst can affect the frontonasal region, which can lead to symptoms similar to FND. Therefore, other options should always be considered in the differential diagnosis.
The diagnostic work up usually includes and MRI of the brain, an EEG, ophthalmic examination and a cardiac ECHO.
Muscle biopsy - which is not commonly done - may show storage of abnormal material and secondary mitochondrial abnormalities in skeletal muscle. Other features that may be seen on muscle biopsy include variability in fibre size, increase in internal and centralized nuclei, type 1 fibre hypotrophy with normally sized type 2 fibres, increased glycogen storage and variable vacuoles on light microscopy
The diagnosis is confirmed by sequencing of the EPG5.
A thorough diagnosis should be performed on every affected individual, and siblings should be studied for deafness, parathyroid and renal disease. The syndrome should be considered in infants who have been diagnosed prenatally with a chromosome 10p defect, and those who have been diagnosed with well defined phenotypes of urinary tract abnormalities. Management consists of treating the clinical abnormalities at the time of presentation. Prognosis depends on the severity of the kidney disease.
Prognoses for 3C syndrome vary widely based on the specific constellation of symptoms seen in an individual. Typically, the gravity of the prognosis correlates with the severity of the cardiac abnormalities. For children with less severe cardiac abnormalities, the developmental prognosis depends on the cerebellar abnormalities that are present. Severe cerebellar hypoplasia is associated with growth and speech delays, as well as hypotonia and general growth deficiencies.
Treatment of otosclerosis can be understood basically under three heads : medical, surgical and amplification.
It is suggested that the diagnostic criteria for Malpuech syndrome should include cleft lip and/or palate, typical associated facial features, and at least two of the following: urogenital anomalies, caudal appendage, and growth or developmental delay.
Due to the relatively high rate of hearing impairment found with the disorder, it too may be considered in the diagnosis. Another congenital disorder, Wolf-Hirschhorn (Pitt-Rogers-Danks) syndrome, shares Malpuech features in its diagnostic criteria. Because of this lacking differentiation, karyotyping (microscopic analysis of the chromosomes of an individual) can be employed to distinguish the two. Whereas deletions in the short arm of chromosome 4 would be revealed with Wolf-Hirschhorn, a karyotype without this aberration present would favor a Malpuech syndrome diagnosis. Also, the karyotype of an individual with Malpuech syndrome alone will be normal.
The diagnosis is usually based on clinical features present at birth.
Ultrasound in the second trimester may show abnormalities associates with NLS, including polyhydramnios, intrauterine growth restriction, microcephaly, proptosis and decreased fetal motility.
There is no cure as of now. Treatment is directed towards the specific symptoms that are present in each individual. Individuals with hearing loss are able to get treated with hearing aids.