What Is The Locus Is Important For Normal Neural Development?

When it comes to neurocognitive disorders and neurodevelopmental disorders, reaserchers have been able to diagnose symptoms of a variety of disorders pertaining to the brain and growth development. Once knowing what the symptoms are behaviors become noticed and there becomes a reason for certain behaviors in individuals allowing different treatments for these disorders..

Describe the child’s temperament, judgment, level of self-awareness, impulsivity, and learning/processing style. Is there a developmental disability? How do these influence the child’s behavior and the responses of caregivers, teachers and other involved professionals?

Babies with dup15q syndrome often have poor muscle tone, known as hypotonia. They may appear "floppy" and have difficulty sucking and feeding. Some parents report that their baby with dup15q syndrome has an unusual, weak cry. Motor milestones such as rolling over, sitting up, and walking are significantly delayed, although most children achieve independent walking after two to three years (younger in children with an interstitial duplication).

Five other gene disorder that contributes to autism are (1) "EN2 (Engrailed 2) involved in cerebellum development. (2) GABR (Gamma Amino Butyric Acid Receptor) regulates brain cell migration. (3) OXTR (Oxytocin Receptor) participating in the response to stress and social skills. (4) RELN (Reelin) involved in neuronal migration in the developing brain. (5) SLC6A4, a serotonin transporter gene” (Johnson, Giarelli, Lewis, & Rice, 2013). As a result of all the researches done several chromosomal loci have been shown to be linked to Autistic Spectrum disorder including those at 2q24-2q31, 7q22-7q31, 7q34-7q36, and 17q11-17q21. Structural chromosomal changes involving deletions and duplication at 7q11, 15q11-15q13, 17p11.2, 22q11.2, and 22q13 have also been associated with forms of autism. However, the most common chromosomal abnormalities currently associated with autism include the fragile X mutation, other sex chromosome abnormalities, and abnormalities of 15q11-q13. “Evidence has shown that duplications of 15q11–q13 have led to higher risks of Autism Spectrum Disorder and developmental and cognitive deficits” (Flashner, Russo, Boileau, Leong, & Gallicano, 2013). Chromosome 15q11-q13.1 region is subject to genomic imprinting, which is an epigenetic process that results in monoallelic gene expression. Duplications lead to autism and are usually maternal in origin. Deletion of the maternal allele of chromosome 15q11-q13 cause Angelman syndrome (AS) a neurodevelopmental disorder

Cri-du-Chat (cat’s cry) Syndrome is a rare chromosomal disorder that is caused by the deletion of genetic material on chromosome 5. Due to this, this syndrome has an alternative name, known as 5p-, or 5p minus syndrome. Although this genetic defect is able to be diagnosed, the cause of the deletion on the chromosome is unknown. Almost all cases of the Cri-du-Chat Syndrome are found to have no relation with family members or previous generations. This syndrome is generally not inherited, as the deletion occurs randomly during meiosis (the formation of the gametes). In about 90% of people who have this condition, the deletion is completely random and is not inherited. The remaining 10% of affected people inherit a chromosome with a deleted section from an unaffected parent. This is because the parents’ balanced

First, the most common, which affects 75% of the population, is resulting from de novo maternal deletions involving chromosome 15q.11.2-913. Second, approximately 25% of the population results in mutations in gene encoding the ubiquitin protein ligase E3A gene. Third, there are 2-3% whom results in AS through imprinting defects. Lastly, 2% of the population results from uniparental disomy of 15q11.2-913, where the child receives two copies of a chromosome from parent and no copies from the other parent. The image below (Figure 1) shows the different genetic mechanisms that cause Angelman syndrome. We have a side-by-side visual of the chromosome and what the defect(s) look like, and where it takes place on the maternal

The most challenging medical diagnosis I have been introduced to is isodicentric chromosome 15 syndrome. This syndrome occurs in about 1 in 30,000 newborns and is a result from having an abnormal extra chromosome in each cell. The chromosome has mirror-image segments instead of a different segment at each

Cri Du Chat Syndrome arises from anomalies in chromosome five . Cri Du Chat Syndrome is found in boys and girls (Pituch et al., 2010). People from all ethnic backgrounds can have Cri Du Chat Syndrome. Most cases are believed to occur during the development of the egg or sperm. A deletion in the p arm of chromosome five results in Cri Du Chat Syndrome (Tyagi, Kumar, Kumar, Singla, and Singh, 2010). The deletion ranges from a partial deletion to a total deletion on the short arm of chromosome five. The deletion could range from region 5p15.3 to a complete loss of the arm (Rodríguez-Caballero et al., 2010). This abnormality is triggered by a small deletion of a single band of DNA. The genetic information on chromosome 5 is missing. Telomerase

At 13 days of life, this young male was admitted to the Neonatal Intensive Care Unit with multiple congenital anomalies including cleft lip and palate, sagittal synostosis, and coarctation of the aorta. A 550 G-band chromosome analysis revealed a karyotype of 46,XY,der(16)t(15;16)(q24;p13.3), consistent with an unbalanced translocation. A whole genome CGH+SNP microarray further defined the chromosome abnormality as a gain of at least 26.83 Megabases at the telomeric region of chromosome 15q and a loss of at least 1.13 Megabases at chromosome 16p13.3 including the alpha globin

Another study states, PWS affects one out of every 10,000 births to 30,000 people globally and affects both males and females of all races and ethnicities (“What is Prader-Willi Syndrome, n.d.”). In addition, people with PWS have a loss of active genes in the region chromosome 15. Furthermore, USA Prader-Willi Syndrome Association (USAPWSA) explains, “In PWS, these critical genes are either missing (deleted) from the father’s chromosome 15, functioning improperly because of an imprinting defect, or the entire chromosome 15 from the father is missing and both chromosome 15s come from the mother.” This complication happens randomly, either during reproductive or embryo development. For instance, our family has no history of obesity or these other complications, yet my niece Janelle has a behavior issue, developmental disorders, and has been diagnosed obese as well as having diabetes type 2 this

Not all chromosomic conditions have a high incidence rate as DS. Those less - known genetic disorders require a robust study by the clinicians to first understand the syndrome and then generate an individualized service plan. Among those conditions, we

usually occurs when there is a deletion in the father’s genes. A deletion is a kind of mutation

During the process of meiosis, usually a single pair of chromosomes will have each member inherited from each parent. Sometimes there are situations where a pair of chromosomes will have each member come from just one parent and not the other. This is called uniparental disomy. Uniparental disomy, or UPD, can sometimes cause abnormalities to the individual it occurs in. Some of the syndromes that UPD causes are Prader-Willi syndrome (PWS), Angelman syndrome (AS), and Beckwith-Widemann Syndrome (BWS). These syndromes have a wide variety of characteristics including mental retardation, seizures, and asymmetric body growth. Uniparental disomy has also been discovered as an aid in some diseases, such as cancer and cystic fibrosis, based on similar

Copy number variations, or CNV’s, are submicroscopic duplications, deletions, or rearrangements of sections of DNA. These variations can vary in length and position on the DNA chromosome and have the potential ability to disrupt gene function. Most of these copy number variations are inherited. Somewhere in the past gene history, an irregularity entered the gene pool and was passed down through generations. Eventually passed to someone who is at risk for autism, this may possibly be a trigger. Some CNVs, however, are not hereditary, but may arise spontaneously either in the egg or sperm. This occurrence happens either before fertilization or in the fertilized egg shortly afterward, referred to as “novo mutations”. This is another example of external factors impacting the occurrence or activation of autism in individuals. Geneticists predict that each person’s DNA may contain several dozen de-novo mutations. The question at hand is how de novo CNVs are associated with

Usually, in early foetal development or cell division, the deletion occurs as genetic mutations.9 However, the deletion can be passed through generations in some cases.2 There might be potential anomalies involved in patient’s family. Genetic counselling and prenatal testing can reduce the rates of birth defects. On the one hand, a genetic testing can be advantageous to other family members, not only for possible future descendants but also long-term health care issues. For extended family members of the patient, cytogenetic testing can prepare for possible risks as well.