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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.
Screening generally only takes place among those displaying several of the symptoms of ABCD, but a study on a large group of institutionalized deaf people in Columbia revealed that 5.38% of them were Waardenburg patients. Because of its rarity, none of the patients were diagnosed with ABCD (Waardenburg Type IV). Nothing can be done to prevent the disease.
The occurrence of WS has been reported to be one in 45,000 in Europe. The diagnosis can be made prenatally by ultrasound due to the phenotype displaying pigmentary disturbances, facial abnormalities, and other developmental defects. After birth, the diagnosis is initially made symptomatically and can be confirmed through genetic testing. If the diagnosis is not made early enough, complications can arise from
Hirschsprung's disease.
Other diseases have similar characteristics to Treacher Collins syndrome. In the differential diagnosis, one should consider the acrofacial dysostoses. The facial appearance resembles that of Treacher Collins syndrome, but additional limb abnormalities occur in those persons. Examples of these diseases are Nager syndrome and Miller syndrome.
The oculoauriculovertebral spectrum should also be considered in the differential diagnosis. An example is hemifacial microsomia, which primarily affects development of the ear, mouth, and mandible. This anomaly may occur bilaterally. Another disease which belongs to this spectrum is Goldenhar syndrome, which includes vertebral abnormalities, epibulbar dermoids and facial deformities.
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.
There is currently no treatment or cure for Waardenburg syndrome. The symptom most likely to be of practical importance is deafness, and this is treated as any other irreversible deafness would be. In marked cases there may be cosmetic issues. Other abnormalities (neurological, structural, Hirschsprung disease) associated with the syndrome are treated symptomatically.
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
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.
Subtypes of the syndrome are traceable to different genetic variations and presentations:
Type III is also known as Klein-Waardenburg syndrome, and type IV is also known as Waardenburg-Shah syndrome.
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.
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.
In terms of diagnosing Bannayan–Riley–Ruvalcaba syndrome there is no current method outside the physical characteristics that may be present as signs/symptoms. There are, however, multiple molecular genetics tests (and cytogenetic test) to determine Bannayan–Riley–Ruvalcaba syndrome.
In general, children with a small isolated nevus and a normal physical exam do not need further testing; treatment may include potential surgical removal of the nevus. If syndrome issues are suspected, neurological, ocular, and skeletal exams are important. Laboratory investigations may include serum and urine calcium and phosphate, and possibly liver and renal function tests. The choice of imaging studies depends on the suspected abnormalities and might include skeletal survey, CT scan of the head, MRI, and/or EEG.
Depending on the systems involved, an individual with Schimmelpenning syndrome may need to see an interdisciplinary team of specialists: dermatologist, neurologist, ophthalmologist, orthopedic surgeon, oral surgeon, plastic surgeon, psychologist.
Genetic changes are related to the following types of Stickler syndrome:
- Stickler syndrome, COL2A1 (75% of Stickler cases)
- Stickler syndrome, COL11A1
- Stickler syndrome, COL11A2 (non-ocular)
- Stickler syndrome, COL9A1 (recessive variant)
Whether there are two or three types of Stickler syndrome is controversial. Each type is presented here according to the gene involved. The classification of these conditions is changing as researchers learn more about the genetic causes.
There is no medical treatment for either syndrome but there are some recommendations that can help with prevention or early identification of some of the problems. Children with either syndrome should have their hearing tested, and adults should be aware that the hearing loss may not develop until the adult years. Yearly visits to an ophthalmologist or other eye care professional who has been informed of the diagnosis of Stickler or Marshall syndrome is important for all affected individuals. Children should have the opportunity to have myopia corrected as early as possible, and treatment for cataracts or detached retinas may be more effective with early identification. Support for the joints is especially important during sports, and some recommend that contact sports should be avoided by those who have very loose joints.
Initially, the clinical presentation of SDS may appear similar to cystic fibrosis. However, CF can be excluded with a normal chloride in sweat test but faecal elastase as a marker of pancreatic function will be reduced. The variation, intermittent nature, and potential for long-term improvement of some clinical features make this syndrome difficult to diagnose. SDS may present with either malabsorption, or hematological problems. Rarely, SDS may present with skeletal defects, including severe rib cage abnormalities that lead to difficulty in breathing. Diagnosis is generally based on evidence of exocrine pancreatic dysfunction and neutropenia. Skeletal abnormalities and short stature are characteristics that can be used to support the diagnosis. The gene responsible for the disease has been identified and genetic testing is now available. Though useful in diagnostics, a genetic test does not surmount the need for careful clinical assessment and monitoring of all patients.
Definitive diagnosis is made by suction biopsy of the distally narrowed segment. A histologic examination of the tissue would show a lack of ganglionic nerve cells. Diagnostic techniques involve anorectal manometry, barium enema, and rectal biopsy.
The suction rectal biopsy is considered the current international gold standard in the diagnosis of Hirschsprung's disease.
Radiologic findings may also assist with diagnosis. Cineanography (fluoroscopy of contrast medium passing anorectal region) assists in determining the level of the affected intestines.
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.
In terms of treatment/management one should observe what signs or symptoms are present and therefore treat those as there is no other current guideline. The affected individual should be monitored for cancer of:
- Thyroid
- Breast
- Renal
Treatment of Aicardi syndrome primarily involves management of seizures and early/continuing intervention programs for developmental delays.
Additional comorbidities and complications sometimes seen with Aicardi syndrome include porencephalic cysts and hydrocephalus, and gastro-intestinal problems. Treatment for porencephalic cysts and/or hydrocephalus is often via a shunt or endoscopic of the cysts, though some require no treatment. Placement of a feeding tube, fundoplication, and surgeries to correct hernias or other gastrointestinal structural problems are sometimes used to treat gastro-intestinal issues.
Nager syndrome is thought to be caused by haploinsufficiency of the spliceosomal factor SF3B4.
Heart-hand syndrome type 3 is very rare and has been described only in three members of a Spanish family. It is also known as Heart-hand syndrome, Spanish type.
Heart-hand syndrome type 2 is also known as Berk–Tabatznik syndrome. Berk–Tabatznik syndrome is a condition with an unknown cause that shows symptoms of short stature, congenital optic atrophy and brachytelephalangy. This condition is extremely rare with only two cases being found.
Nager acrofacial dysostosis is a genetic congenital anomaly syndrome. Nager syndrome displays several or all of the following characteristics: underdevelopment of the cheek and jaw area, down-sloping of the opening of the eyes, lack or absence of the lower eyelashes, kidney or stomach reflux, hammer toes, shortened soft palate, lack of development of the internal and external ear, possible cleft palate, underdevelopment or absence of the thumb, hearing loss (see hearing loss with craniofacial syndromes) and shortened forearms, as well as poor movement in the elbow, and may be characterized by accessory tragi. Occasionally, affected individuals develop vertebral anomalies such as scoliosis. The inheritance pattern is said to be autosomal but there are arguments as to whether it is autosomal dominant or autosomal recessive. Most cases tend to be sporadic. Nager syndrome is also linked to five other similar syndromes: Miller syndrome, Treacher Collins, Pierre Robin, Genee-Wiedemann, and Franceschetti-Zwahlen-Klein.