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Molecular (DNA) testing for PAX6 gene mutations (by sequencing of the entire coding region and deletion/duplication analysis) is available for isolated aniridia and the Gillespie syndrome. For the WAGR syndrome, high-resolution cytogenetic analysis and fluorescence in situ hybridization (FISH) can be utilized to identify deletions within chromosome band 11p13, where both the PAX6 and WT1 genes are located.
MRI will help with the diagnosis of structural abnormality of the brain. Genetic testing may also be pursued.
The most extensive epidemiological survey on this congenital malformation has been carried out by Dharmasena et al and using English National Hospital Episode Statistics, they calculated the annual incidence of anophthalmia, microphthalmia and congenital malformations of orbit/lacrimal apparatus from 1999 to 2011. According to this study the annual incidence of congenital microphthalmia in the United Kingdom was 10.8 (8.2 to 13.5) in 1999 and 10.0 (7.6 to 12.4) in 2011.
ONH is diagnosed by ophthalmoscopic examination. Patients with ONH exhibit an optic nerve that appears smaller than normal and different in appearance from small optic nerves caused by other eye conditions such as optic (nerve) atrophy.
DM:DD ratio has proven to be a clinically useful measurement to help diagnose optic nerve hypoplasia. Where "DM" represents the distance from Disk to Macula, and "DD" represents Disc Diameter.
The mean disc diameter (DD) is (Vertical diameter of Disc+Horizontal diameter of Disc)divided by 2. The distance between the center of the disc and the macula is DM.
"Interpretation:" When the ratio of DM to DD is greater than 3, ONH is suspected, and when it is greater than 4, Optic Nerve Hypoplasia is definite.
If the medical history and the actual exam of the hemangioma look typical for PHACE Syndrome, more tests are ordered to confirm the diagnosis. These tests may include:
- Ultrasound
- Magnetic resonance imaging (MRI)
- Magnetic resonance angiography of the brain (MRA)
- Echocardiogram
- Eye exam by an eye doctor
- Other tests may be needed for diagnosis and treatment
Current research is focusing on clearly defining the phenotype associated with tetrasomy 18p and identifying which genes cause medical and developmental problems when present in four copies.
Typically a coloboma appears oval or comet shaped with round end towards the centre. There may be a few vessels (retinal or choroidal) at the edges. The surface may have irregular depression.
The diagnosis of Muenke syndrome is suspected bases on abnormal skull shape and a diagnosis of coronal craniosynostosis. In 2006, Agochukwu and her colleagues concluded that “A distinct Muenke syndrome phenotype includes: uni or bilateral coronal synostosis, midface hypoplasia, broad toes, and brachydactyly.” Due to phenotypic overlap and/or mild phenotypes, clinical differentiation of this syndrome may be difficult. The suspected diagnosis is confirmed by a blood test to check for gene mutation. To establish the extent of disease in an individual diagnosed with Muenke syndrome, various evaluations are recommended.
Suspicion of a chromosome abnormality is typically raised due to the presence of developmental delays or congenital malformations. Diagnosis of tetrasomy 18p is typically made via a routine chromosome analysis from a blood sample. The diagnosis can also be made prenatally by chorionic villus sampling or amniocentesis.
Severity of tetrasomy 18p is variable. Individuals with mosaicism are typically less severely affected than non-mosaic individuals.
Genetic testing for CHARGE syndrome involves specific genetic testing for the CHD7 gene. The test is available at most major genetic testing laboratories. Insurance companies sometimes do not pay for such genetic tests, though this is changing rapidly as genetic testing is becoming standard across all aspects of medicine. CHARGE syndrome is a clinical diagnosis, which means genetic testing is not required in order to make the diagnosis. Rather, the diagnosis can be made based on clinical features alone.
Colobomas of the iris may be treated in a number of ways. A simple cosmetic solution is a specialized cosmetic contact lens with an artificial pupil aperture. Surgical repair of the iris defect is also possible. Surgeons can close the defect by stitching in some cases. More recently artificial iris prosthetic devices such as the Human Optics artificial iris have been used successfully by specialist surgeons. This device cannot be used if the natural lens is in place and is not suitable for children. Suture repair is a better option where the lens is still present.
Vision can be improved with glasses, contact lenses or even laser eye surgery but may be limited if the retina is affected or there is amblyopia.
The visual prognosis in optic nerve hypoplasia is quite variable. Occasionally, optic nerve hypoplasia may be compatible with near-normal vision; in other cases, one or both eyes may be functionally, or legally blind. Although most patients with only optic nerve involvement lead normally productive lives, those with accompanying endocrine dysfunction or other midline cerebral abnormalities are more at risk for on-going intellectual and other disabilities.
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.
Prenatal Diagnosis:
- Aymé, "et al." (1989) reported prenatal diagnosis of Fryns syndrome by sonography between 24 and 27 weeks.
- Manouvrier-Hanu et al. (1996) described the prenatal diagnosis of Fryns syndrome by ultrasonographic detection of diaphragmatic hernia and cystic hygroma. The diagnosis was confirmed after termination of the pregnancy. The fetus also had 2 erupted incisors; natal teeth had not been mentioned in other cases of Fryns syndrome.
Differential Diagnosis:
- McPherson et al. (1993) noted the phenotypic overlap between Fryns syndrome and the Pallister–Killian syndrome (601803), which is a dysmorphic syndrome with tissue-specific mosaicism of tetrasomy 12p.
- Veldman et al. (2002) discussed the differentiation between Fryns syndrome and Pallister–Killian syndrome, noting that differentiation is important to genetic counseling because Fryns syndrome is an autosomal recessive disorder and Pallister–Killian syndrome is usually a sporadic chromosomal aberration. However, discrimination may be difficult due to the phenotypic similarity. In fact, in some infants with 'coarse face,' acral hypoplasia, and internal anomalies, the initial diagnosis of Fryns syndrome had to be changed because mosaicism of isochromosome 12p was detected in fibroblast cultures or kidney tissue. Although congenital diaphragmatic hernia is a common finding in both syndromes, bilateral congenital diaphragmatic hernia had been reported only in patients with Fryns syndrome until the report of the patient with Pallister–Killian syndrome by Veldman et al. (2002).
- Slavotinek (2004) reviewed the phenotypes of 52 reported cases of Fryns syndrome and reevaluated the diagnostic guidelines. She concluded that congenital diaphragmatic hernia and distal limb hypoplasia are strongly suggestive of Fryns syndrome, with other diagnostically relevant findings including pulmonary hypoplasia, craniofacial dysmorphism, polyhydramnios, and orofacial clefting. Slavotinek (2004) stated that other distinctive anomalies not mentioned in previous guidelines include ventricular dilatation or hydrocephalus, agenesis of the corpus callosum, abnormalities of the aorta, dilatation of the ureters, proximal thumbs, and broad clavicles.
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.
Once the diagnosis is made based on clinical signs, it is important to investigate other body systems that may be involved. For example, if the diagnosis is made based on the abnormal appearance of the ears and developmental delay, it is important to check the child's hearing, vision, heart, nose, and urogenital system. Ideally, every child newly diagnosed with CHARGE syndrome should have a complete evaluation by an ENT specialist, audiologist, ophthalmologist, pediatric cardiologist, developmental therapist, and pediatric urologist.
The outcome of this disease is dependent on the severity of the cardiac defects. Approximately 1 in 3 children with this diagnosis require shunting for the hydrocephaly that is often a consequence. Some children require extra assistance or therapy for delayed psychomotor and speech development, including hypotonia.
Laboratory investigations usually show elevated creatine kinase, myopathic/dystrophic muscle pathology and altered α-dystroglycan. Antenatal diagnosis is possible in families with known mutations. Prenatal ultrasound may be helpful for diagnosis in families where the molecular defect is unknown.
Aniridia may be broadly divided into hereditary and sporadic forms. Hereditary aniridia is usually transmitted in an autosomal dominant manner (each offspring has a 50% chance of being affected), although rare autosomal recessive forms (such as Gillespie syndrome) have also been reported. Sporadic aniridia mutations may affect the WT1 region adjacent to the AN2 aniridia region, causing a kidney cancer called nephroblastoma (Wilms tumor). These patients often also have genitourinary abnormalities and intellectual disability (WAGR syndrome).
Several different mutations may affect the PAX6 gene. Some mutations appear to inhibit gene function more than others, with subsequent variability in the severity of the disease. Thus, some aniridic individuals are only missing a relatively small amount of iris, do not have foveal hypoplasia, and retain relatively normal vision. Presumably, the genetic defect in these individuals causes less "heterozygous insufficiency," meaning they retain enough gene function to yield a milder phenotype.
- AN
- Aniridia and absent patella
- Aniridia, microcornea, and spontaneously reabsorbed cataract
- Aniridia, cerebellar ataxia, and mental deficiency (Gillespie syndrome)
The presence of a small eye within the orbit can be a normal incidental finding but in most cases it is abnormal and results in blindness. The incidence is 14 per 100,000 and the condition affects 3-11% of blind children.
Norrie disease and other NDP related diseases are diagnosed with the combination of clinical findings and molecular genetic testing. Molecular genetic testing identifies the mutations that cause the disease in about 85% of affected males. Clinical diagnoses rely on ocular findings. Norrie disease is diagnosed when grayish-yellow fibrovascular masses are found behind the eye from birth through three months. Doctors also look for progression of the disease from three months through 8–10 years of age. Some of these progressions include cataracts, iris atrophy, shallowing of anterior chamber, and shrinking of the globe. By this point, people with the condition either have only light perception or no vision at all.
Molecular genetic testing is used for more than an initial diagnosis. It is used to confirm diagnostic testing, for carrier testing females, prenatal diagnosis, and preimplantation genetic diagnosis. There are three types of clinical molecular genetic testing. In approximately 85% of males, mis-sense and splice mutations of the NDP gene and partial or whole gene deletions are detected using sequence analysis. Deletion/duplication analysis can be used to detect the 15% of mutations that are submicroscopic deletions. This is also used when testing for carrier females. The last testing used is linkage analysis, which is used when the first two are unavailable. Linkage analysis is also recommended for those families who have more than one member affected by the disease.
On MRI the retinal dysplasia that occurs with the syndrome can be indistinguishable from persistent hyperplastic primary vitreous, or the dysplasia of trisomy 13 and Walker–Warburg syndrome.
In utero exposure to cocaine and other street drugs can lead to septo-optic dysplasia.
Genetic counseling for VWS involves discussion of disease transmission in the autosomal dominant manner and possibilities for penetrance and expression in offspring. Autosomal dominance means affected parents have a 50% chance of passing on their mutated "IRF6" allele to a their child. Furthermore, if a cleft patient has lip pits, he or she has a ten times greater risk of having a child with cleft lip with or without cleft palate than a cleft patient who does not have lip pits. Types of clefting between parents and affected children are significantly associated; however, different types of clefts may occur horizontally and vertically within the same pedigree. In cases where clefting is the only symptom, a complete family history must be taken to ensure the patient does not have non-syndromic clefting.
The treatment of Muenke syndrome is focused on the correction of the abnormal skull shape and mirrors the treatment of coronal craniosynostosis. The abnormal growth patterns continue throughout the growing years; therefore, intervention, accurate diagnosis, and a customized, expertly carried-out treatment plan should be a primary concern. The treatment of Muenke syndrome is focused on correction of the abnormal skull shape and mirrors the treatment of non-syndromic coronal craniosynostosis. Although the timing of surgery can be highly individualized, surgical correction of the bicoronal craniosynostosis is most often done between 6 and 12 months of age. Surgery is usually performed through a scalp incision that lies concealed within the hair of the head. Your craniofacial surgeon will work in concert with a pediatric neurosurgeon in order to safely remove the bones of the skull. Then, the craniofacial surgeon reshapes and repositions those bones to give a more normal skull shape.
Usually the hemangioma requires medical therapy. The child may need other therapies, depending on what other organs or structures are involved.