Deletion is a mutation in which a part of the chromosome or the DNA is absent or lost. It may be inherent, or it may be due to improper chromosomal crossing-over during meiosis. This deletion is responsible for the abnormalities in the patient. One of the known disorders seen due to deletion is the Wolf-Hirschhorn syndrome.
Wolf-Hirschhorn syndrome (WHS), first described by Wolf et al[1] and Hirschhorn et al[2], results from the hemizygous deletion of the distal short arm of chromosome 4. Due to the complex and unmarked expression of this disorder, the WHS syndrome is presumed to be a contiguous gene syndrome with an indeterminate number of genes responsible for the phenotype i.e. a multigenic etiology. [3][4]
The size of the terminal deletion may vary from a subtle 1.4Mb to a classic 30Mb [5]. Earlier genotype-phenotype correlation studies reveal that the main characteristic feature of WHS - the ‘Greek warrior helmet face’, is caused due to the hemizygosity of the WHSC1 gene located in the WHS critical region (WHSCR).[5] Various other genes are also located in the WHSCR which are responsible for most other phenotypic features. More precisely, the Wolf-Hirschhorn syndrome critical region (WHSCR) is located at 4p16.3 region. Approximately 25% of the patients with WHS deletion in this region are not detectable by cytogenetic karyotyping [6]. Hence, FISH has to be performed.
The prevalence of this syndrome is estimated to be 1 in 50,000 births [7] with a female to male ratio of 2:1[8].
Case report:
A baby was born with low birth weight of 1.8 kg to a 36 yr old father and 32 yr old mother. The proposita is the 6th girl child of the non-consanguineous parents. As can be seen from the pedigree chart shown in figure 2, the mothe...
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...infant with Wolf-Hirschhorn syndrome: a dilemma in determination of the optimal timing of delivery. Clinical Medicine: Case reports.
8. Society for the Study of Behavioral Phenotypes (SSBP) Information sheet: Wolf-Hirschhorn syndrome. Registered Charity number 1013849.
9. Altherr, M.R., Bengtsson, U., Elder, F. F. B., Ledbetter, D. H., Wasmuth, J. J., McDonald, M.E., Gusella, J. F., Greenberg, F. Molecular confirmation of Wolf-Hirschhorn syndrome with a subtle translocation of chromosome 4. Am. J. Hum. Genet. 49: 1235-1242, 1991. [PubMed: 1746553]
10. Althea T. Impact of chromosome 4p-syndrome on communication and expressive language skills: A preliminary investigation. Language, Speech and Hearing Services in Schools. Vol 41 265-276 July 2010.
11. Harold Chen. EMedicine Specialties> Pediatrics: Genetics and Metabolism Disease> Genetics. Updated Jun 16, 2009.
Sex-linked disorders only affect males and are passed down through female carriers. A boy inherits the disorder when he receives an X chromosome with a mutated dystrophin gene (the genetic cause) from his mother. The dystrophin gene is the largest gene found in nature and was identified through a positional cloning approach. It's a highly complex gene, a large rod-like cytoskeletal protein which is found at the inner surface of muscle fibers. www.ncbi.nlm.nih.gov - http://www.ncbi.nlm.nih.gov/.
Achondroplasia (ACH) is the most common form of short-limb dwarfism occuring in 1 in 15,000 to 28,000 births and appears to be slightly more prevalent in females, but indiscriminent toward race (1-3). Evidence has been found in Egypt for cases of ACH dating back as far as 4500 B.C. (4). In simplest terms, ACH is a disease where the dwarfing of bones formed in the cartilage occurs (5). There are many features that accompany this disease including rhizomelic (proximal) shortening of the extremities, megalencephaly (enlarged brain), short stature, trident hand, and frontal bossing (prominent forehead) (1, 3, 4, 6-8). Expression of this gene at high levels is primarily found in cells of the nervous system and the cartilage rudiments and chondrocytes in the growth plates of developing bone (7, 9). Due to the fact that there are numerous types of skeletal dysplasia, some which appear similar to ACH at times, the only way for complete confirmation is to perform molecular techniques such as genetic testing (1, 4, 8).
The range and severity of symptoms and findings may be extremely variable, including among affected members of the same family. However, primary findings may include premature closure of the fibrous joints between certain bones of the skull, unusually flat, underdeveloped midfacial regions abnormally broad great toes, and/or malformation or fusion of certain bones within the feet. In some cases, Jackson-Weiss Syndrome may result from new genetic changes that appear to occur randomly for unknown reasons. In other affected individuals, the disorder may be inherited. Mutations in the FGFR2 gene cause Jackson–Weiss syndrome. The FGFR2 gene produces a protein called
(Calendar 2013) Waardenburg Syndrome is a rare genetic disorder meaning that is caused by a mutation of genes. The disorder is classified as type I, II, III, or IV based on inheritance pattern and symptoms (Genetics 2013). Waardenburg Syndrome is an incurable disorder that is inherited from either one or both parents. If it came from one parent, it is an autosomal dominant pattern and if it came from both, it is known as an autosomal recessive pattern (Calendar 2013).
Peterson-Iyer, Karen. "Confronting a Fetal Abnormality." http://www.scu.edu. Santa Clara University, Jan. 2008. Web. 13 Mar. 2014. .
In 1993 a consortium of researchers who worked on the DNA samples from families in the Lake Maracaibo region of Venezuela, an area with a high density of HD and significant consanguinity, reported the successful discovery of the gene responsible for the occurrence of this disease, present in chromosome 4 and named it as IT15 (Interesting transcript #15). IT15 later called as the Huntingtin gene (HTT) [2]. HTT is ~10 kilobases (kb) long and translated into a protein of 3144 amino acids with anticipated molecular mass of 348 kDa. Huntigtin protein is expressed in in human and all mammalian cells, where brain and testis has the highest concentration; liver...
Girls with this syndrome may have many middle ear infections during childhood; if not treated, these chronic infections could cause hearing loss. Up to the age of about 2 years, growth in height is approximately normal, but then it lags behind that of other girls. Greatly reduced growth in height of a female child should lead to a chromosome test if no diagnosis has already been made. Early diagnosis is very importance in order to be able to give enough correct information to the parents, and gradually to the child herself, so that she has the best possibilities for development. Early diagnosis is also important in case surgical treatment of the congenital heart defect (seen in about 20 per cent of cases) is indicated.
The most common way of getting Angelman syndrome is through chromosome deletion. This is responsible for about 68% of all cases o...
Owens, Robert E., Dale E. Metz, and Kimberly A. Farinella. Introduction to Communication Disorders: A Lifespan Evidence-Based Perspective. Four ed. Upper Saddle River: Pearson Education, 2011. 194-216. Print.
Low birth weight (LBW) has become a public health problem in many regions of the world and it is the predominant cause of infant mortality. According to statistics of World Health Organization, there are about 30 million of low birth weight babies born in the world annually. Low Birth weight can be defined as the birth weight of a new born baby of less than 2.500 Kg regardless their gestational age at birth. This can be seen on both preterm babies as well as mature babies who have slow prenatal growth rate. Infants who are Low Birth Weight are more likely to have both short term and long term severe health consequences.
In the following studies, the various strengths and weaknesses of the language and communication of individuals with Down syndrome (DS) are reviewed and discussed. Language is defined as the method of human communication, either spoken or written, consisting of the use of words, in a structured or conventional way. Communication is the interaction or exchange of information or news (Webster, 2013). Down syndrome, a genetic disorder, is the most common cause of intellectual disabilities, occurring at an average of one out of every 700 births (CDS, 2006). This disorder is caused by the extra chromosome 21 (also known as Trisomy 21).
The desire to have a "normal" child is held by every parent and only now are we beginning to have the ability to select for that child. In preparation to receiving genetic testing, the parents are required to meet with a genetic counselor. A detailed description of the testing methods are reviewed with the couple as well as the risks which are involved with each. Upon an understanding of the procedures, the counselor discusses the many possible outcomes which could be the result of the diagnosis. Finally, before any tests are performed, anxieties from either of the parents are addressed as well as the psychological well-being of the parents.
Birth of a baby is the start of a new era of a generation. As the new born infants are the internodes of the future, In order to have a health and strength population they should be given the proper health status from the beginning of their life. From the birth an infant can cause lot of health risks such as birth defects, severe organ damages or functional problems and even the death. All most all the above health risks are occurred due to the nutritional problems as well as the physical damages. With the reference of most out coming results in the world, as LBW contributes to 60% to 80% of all neonatal deaths, the Low birth weight (LBW) has become a common problem that occurs at the first step of infants’ life and moreover it has become a severe problem as the health risks due to the Low birth weight can be even seen at the adulthood of a person who are born with low birth weight.
GSD I is an inherited autosomal recessive disorder with the incidence being 1 in 100,000. Parents may be heterozygote carriers, making them asymptomatic, however they have a 25% chance of having a child that is affected by GSD I. Prenatal diagnosis can be made by completing a liver biopsy at 18-22 weeks but no fetal treatments are currently available and standard newborn screening tests are not able to detect GSD I.
Communication is very crucial in life, especially in education. Whether it be delivering a message or receiving information, without the ability to communicate learning can be extremely difficult. Students with speech and language disorders may have “trouble producing speech sounds, using spoken language to communicate, or understanding what other people say” (Turkington, p10, 2003) Each of these problems can create major setbacks in the classroom. Articulation, expression and reception are all essential components for communication. If a student has an issue with articulation, they most likely then have difficulty speaking clearly and at a normal rate (Turkington, 2003). When they produce words, they may omit, substitute, or even distort sounds, hindering their ability to talk. Students who lack in ways of expression have problems explaining what they are thinking and feeling because they do not understand certain parts of language. As with all types of learning disabilities, the severity can range. Two extreme cases of expression disorders are dysphasia and aphasia, in which there is partial to no communication at all (Greene, 435, 2002). Individuals can also have a receptive disorder, in which they do not fully comprehend and understand information that is being given to them. They can experience problems making sense of things. “Children may hear or see a word but not be able to understand its meaning” (National Institutes of Health, 1993, p1). Whether children have difficulty articulating speech, expressing words, receiving information, or a combination of the three, there is no doubt that the tasks given to them in school cause frustration. These children experience anxiety when...