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Tests are either conducted at birth, or later in early childhood via: fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA), array comparative genomic hybridization (aCGH), and EHMT1 sequencing.
FISH is a screening test that uses multicolour probes or comparative genomic hybridization to find any chromosome irregularities in a genome. It can be used for gene mapping, detecting aneuploidy, locating tumours etc. The multicolour probes attach to a certain DNA fragment. MLPA is a test that finds and records DNA copy change numbers through the use of PCR. MLPA can be used to detect tumours in the glial cells of the brain, as well as chromosomal abnormalities. Array-based comparative genomic hybridization (aCGH) tracks chromosome deletions and or amplifications using fluorescent dyes on genomic sequences of DNA samples. The DNA samples (which are 25-80 base pairs in length) are then placed on slides to be observed under microscope. Lastly, EHMT1 sequencing is a process in which a single-strand of DNA from the EHMT1 gene is removed, and DNA polymerase is added in order to synthesize complementary strands. In turn, this allows scientists to map out a person's DNA sequence allowing for a diagnosis to be made.
Due to its recent discovery, there are currently no existing treatments for Kleefstra syndrome.
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.
Most individuals with this condition do not survive beyond childhood. Individuals with MDS usually die in infancy and therefore do not live to the age where they can reproduce and transmit MDS to their offspring.
While no cure for MDS is available yet, many complications associated with this condition can be treated, and a great deal can be done to support or compensate for functional disabilities. Because of the diversity of the symptoms, it can be necessary to see a number of different specialists and undergo various examinations, including:
- Developmental evaluation
- Cardiologists evaluation
- Otolaryngology
- Treatment of seizures
- Urologic evaluation
- Genetic counseling-balanced chromosomal translocation should be excluded in a parents with an affected child are planning another pregnancy, so parents with affected children should visit a genetic counselor.
MORM syndrome is a genetic disorder obtained through inheritance. The main method for testing individuals showing symptoms of MORM syndrome is sequence analysis of the entire coding region. When performing a sequence analysis of the entire coding region the gene INNP5E is targeted. Sequence analysis is the biotechnological process in which the structure and sequence of DNA, RNA, or protein sequence is determined through the use of technology. The sequence can then be analyzed to determine mutations or abnormalities in that particular region. When testing for MORM syndrome, sequence analysis of the region of the genome which contains the gene INPP5E is targeted and examined to look for mutations.
The duplication involved in PTLS is usually large enough to be detected through G-banding alone, though there is a high false negative rate. To ascertain the diagnosis when karyotyping results are unclear or negative, more sophisticated techniques such as subtelomeric fluorescent in-situ hybridization analysis and array comparative genomic hybridization (aCGH) may be used.
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
Treatment of cause: Due to the genetic cause, no treatment of the cause is possible.
Treatment of manifestations: routine treatment of ophthalmologic, cardiac, and neurologic findings; speech, occupational, and physical therapies as appropriate; specialized learning programs to meet individual needs; antiepileptic drugs or antipsychotic medications as needed.
Surveillance: routine pediatric care; routine developmental assessments; monitoring of specific identified medical issues.
SMS is usually confirmed by blood tests called chromosome (cytogenetic) analysis and utilize a technique called FISH (fluorescent in situ hybridization). The characteristic micro-deletion was sometimes overlooked in a standard FISH test, leading to a number of people with the symptoms of SMS with negative results.
The recent development of the FISH for 17p11.2 deletion test has allowed more accurate detection of this deletion. However, further testing is required for variations of Smith–Magenis syndrome that are caused by a mutation of the "RAI1" gene as opposed to a deletion.
Children with SMS are often given psychiatric diagnoses such as autism, attention deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), attention deficit disorder (ADD) and/or mood disorders.
Y chromosome microdeletion is currently diagnosed by extracting DNA from leukocytes in a man's blood sample, mixing it with some of the about 300 known genetic markers for sequence-tagged sites (STS) on the Y chromosome, and then using polymerase chain reaction amplification and gel electrophoresis in order to test whether the DNA sequence corresponding to the selected markers is present in the DNA.
Such procedures can test only the integrity of a tiny part of the overall 23 million base pair long Y chromosome, therefore the sensitivity of such tests depends on the choice and number of markers used. Present diagnostic techniques can only discover certain types of deletions and mutations on a chromosome and give therefore no complete picture of genetic causes of infertility. They can only demonstrate the presence of some defects, but not the absence of any possible genetic defect on the chromosome.
The gold standard test for genetic mutation, namely complete DNA sequencing of a patient's Y chromosome, is still far too expensive for use in epidemiologic research or even clinical diagnostics.
Techniques used to diagnose this disorder are fluorescence in situ hybridization (FISH) and microarrays. FISH uses fluorescent dyes to visualize sections under a microscope, but some changes are too small to see. Microarray comparative genomic hybridization (array CGH) shows changes in small amounts DNA on chromosomes.
Diagnosis is usually based on clinical findings, although fetal chromosome testing will show trisomy 13. While many of the physical findings are similar to Edwards syndrome there are a few unique traits, such as polydactyly. However, unlike Edwards syndrome and Down syndrome, the quad screen does not provide a reliable means of screening for this disorder. This is due to the variability of the results seen in fetuses with Patau.
The diagnosis of this syndrome can be made on clinical examination and perinatal autopsy.
Koenig and Spranger (1986) noted that eye lesions are apparently nonobligatory components of the syndrome. The diagnosis of Fraser syndrome should be entertained in patients with a combination of acrofacial and urogenital malformations with or without cryptophthalmos. Thomas et al. (1986) also emphasized the occurrence of the cryptophthalmos syndrome without cryptophthalmos and proposed diagnostic criteria for Fraser syndrome. Major criteria consisted of cryptophthalmos, syndactyly, abnormal genitalia, and positive family history. Minor criteria were congenital malformation of the nose, ears, or larynx, cleft lip and/or palate, skeletal defects, umbilical hernia, renal agenesis, and mental retardation. Diagnosis was based on the presence of at least 2 major and 1 minor criteria, or 1 major and 4 minor criteria.
Boyd et al. (1988) suggested that prenatal diagnosis by ultrasound examination of eyes, digits, and kidneys should detect the severe form of the syndrome. Serville et al. (1989) demonstrated the feasibility of ultrasonographic diagnosis of the Fraser syndrome at 18 weeks' gestation. They suggested that the diagnosis could be made if 2 of the following signs are present: obstructive uropathy, microphthalmia, syndactyly, and oligohydramnios. Schauer et al. (1990) made the diagnosis at 18.5 weeks' gestation on the basis of sonography. Both the female fetus and the phenotypically normal father had a chromosome anomaly: inv(9)(p11q21). An earlier born infant had Fraser syndrome and the same chromosome 9 inversion.
Van Haelst et al. (2007) provided a revision of the diagnostic criteria for Fraser syndrome according to Thomas et al. (1986) through the addition of airway tract and urinary tract anomalies to the major criteria and removal of mental retardation and clefting as criteria. Major criteria included syndactyly, cryptophthalmos spectrum, urinary tract abnormalities, ambiguous genitalia, laryngeal and tracheal anomalies, and positive family history. Minor criteria included anorectal defects, dysplastic ears, skull ossification defects, umbilical abnormalities, and nasal anomalies. Cleft lip and/or palate, cardiac malformations, musculoskeletal anomalies, and mental retardation were considered uncommon. Van Haelst et al. (2007) suggested that the diagnosis of Fraser syndrome can be made if either 3 major criteria, or 2 major and 2 minor criteria, or 1 major and 3 minor criteria are present in a patient.
Microdeletions in the Y chromosome have been found at a much higher rate in infertile men than in fertile controls and the correlation found may still go up as improved genetic testing techniques for the Y chromosome are developed.
Much study has been focused upon the "azoospermia factor locus" (AZF), at Yq11. A specific partial deletion of AZFc called "gr/gr deletion" is significantly associated with male infertility among Caucasians in Europe and the Western Pacific region.
Additional genes associated with spermatogenesis in men and reduced fertility upon Y chromosome deletions include RBM, DAZ, SPGY, and TSPY.
Potocki–Shaffer syndrome can be detected through array comparative genomic hybridization (aCGH).
Some symptoms can be managed with drug therapy, surgery and rehabilitation, genetic counselling, and palliative care.
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
A 'de novo'-situation appears in about 75% of the cases. In 25% of the cases, one of the parents is carrier of the syndrome, without any effect on the parent. Sometimes adults have mild problems with the syndrome. To find out whether either of the parents carries the syndrome, both parents have to be tested. In several cases, the syndrome was identified with the child, because of an autism disorder or another problem, and later it appeared that the parent was affected as well. In families where both parents have tested negative for the syndrome, chances of a second child with the syndrome are extremely low. If the syndrome was found in the family, chances of a second child with the syndrome are 50%, because the syndrome is autosomal dominant. The effect of the syndrome on the child cannot be predicted.
As of October 2012, Unique, an international rare chromosome disorder group and registry, has 64 genetically-confirmed cases of this deletion worldwide.
The Syndrome can be detected with fluorescence in situ hybridization.
For parents with a child with the syndrome, it is advisable to consult a physician before another pregnancy.
While only a few adults have been reported with 2q37 microdeletion syndrome, it is predicted that this number will rise as various research studies continue to demonstrate that most with the disorder do not have a shortened life span.
Currently there are no open research studies for otodental syndrome. Due to the rarity of this disease, current research is very limited.
The most recent research has involved case studies of the affected individuals and/or families, all of which show the specific phenotypic symptoms of otodental syndrome. Investigations on the effects of FGF3 and FADD have also been performed. These studies have shown successes in supporting previous studies that mutations to FGF3 and neighboring genes may cause the associated phenotypic abnormalities. According to recent studies involving zebrafish embryos, there is also support in that the FADD gene contributed to ocular coloboma symptoms as well.
Future research studies are required in order to better grasp the specific relationship between the gene involved and its effect on various tissues and organs such as teeth, eyes, and ear. Little is known and there is still much to be determined.
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.
Prenatal testing may be used to identify the existence of NF-1 in the fetus. For embryos produced via in vitro fertilisation, it is possible via preimplantation genetic diagnosis to screen for NF-1.
Chorionic villus sampling or amniocentesis can be used to detect NF-1 in the fetus.
People with NF-1 have a 50% percent chance of passing the disorder on to their kids, but people can have a child born with NF-1 when they themselves do not have it. This is caused in a spontaneous change in the genes during pregnancy.
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.
At the 2005 American Society of Human Genetics meeting, Francis Collins gave a presentation about a treatment he devised for children affected by Progeria. He discussed how farnesyltransferase inhibitor (FTI) affects H-Ras. After his presentation, members of the Costello Syndrome Family Network discussed the possibility of FTIs helping children with Costello syndrome. Mark Kieran, who presented at the 1st International Costello Syndrome Research Symposium in 2007, agreed that FTIs might help children with Costello syndrome. He discussed with Costello advocates what he had learned in establishing and running the Progeria clinical trial with an FTI, to help them consider next steps.
Another medication that affects H-Ras is Lovastatin, which is planned as a treatment for neurofibromatosis type I. When this was reported in mainstream news, the Costello Syndrome Professional Advisory Board was asked about its use in Costello Syndrome. Research into the effects of Lovastatin was linked with Alcino Silva, who presented his findings at the 2007 symposium. Silva also believed that the medication he was studying could help children with Costello syndrome with cognition.
A third medication that might help children with Costello syndrome is a MEK inhibitor that helps inhibit the pathway closer to the cell nucleus.
More than 80% of children with Patau syndrome die within the first year of life. Children with the mosaic variation are usually affected to a lesser extent. In a retrospective Canadian study of 174 children with trisomy 13, median survival time was 12.5 days. One and ten year survival was 19.8% and 12.9% respectively.