¶ … Human Genetics Inheritable neuropathies are among the globe's healthcare challenges today. Although their incidence is not as high, one in every 2500 people, as compared to other major healthcare problems, their symptoms, and consequences are equally fatal. Charcot Marie Tooth disease is among the inherited neuropathies, which has significantly shown potential and fatal consequences to people. Notably, the disorder does not have any known cure, but there are numerous therapies to control the disease. Although this is the current case, advancements in medicine, are gradually bearing fruits because experts have discovered a way to diagnose some types of these deadly disorders. Other types of neuropathy disorders include hereditary neuropathy with liability to pressure palsy (HNNP), hereditary motor neuropathy (HMN), and hereditary sensory and autonomic neuropathy (HSAN or hereditary sensory neuropathy). In a second part of this paper is an experiment to detect HaeIII in given human DNA samples. Owing to the experiment, the paper will use some given samples to detect the presence of the mentioned enzyme. This experiment is a step towards advancement of forensic investigations, another global challenge today, evident in the cruel crimes experienced.

Introduction

Charcot Marie Tooth disease (CMT) is a heritable peripheral neuropathy, which affects one in every 2,500 people. Owing to its prevalence, Sarpota et al. (2011) suggests that it is the most commonly inherited neurological disorder. People with this disorder experience predicaments with their feet and hands, characterized by feet deformity, foot drop, and unusual sensations; however, people with the disorder may experience different challenges. In addition, the people with CMT have autosomal (AD) dominant inheritance (Sarpota et al., 2011), but majority of them will have CMT with X-linked or autosomal recessive (AR) inheritance.

Most importantly, this disease is not predisposed to any gender, or age; it can affect both men and women, from any race or ethnic lines. In addition, it can appear at any time in life, but research suggests that many patients test positive for the disorder during infancy or early childhood. In this case, they develop severe disability, when compared to patients diagnosed with the disorder in adulthood. On the other hand, there is evidence that it may appear after two decades of life (Murphy et al., 2012). In such a case, the patients will experience distal weakness, sensory loss, foot deformities, and absent ankle reflexes.

Notably, a good percentage of the CMT neuropathies appear to be primary axonal disorders. Apart from Charcot Marie Tooth disease, other inherited neuropathies include hereditary neuropathy with liability to pressure palsy (HNNP), hereditary motor neuropathy (HMN), and hereditary sensory and autonomic neuropathy (HSAN or hereditary sensory neuropathy) (Murphy et al., 2012). The disorders are a major cause of global healthcare challenges, especially because there are over 45 mutations, known and others remain unknown, associated to causing the inherited neuropathies. Nevertheless, research suggests that there are clinical similarities among people suffering from CMT, but owing to its diverse nature, it exists in numerous forms.

These include AD demyelinating (CMT1), AD axonal (CMT2), AR (CMT4) and X-linked (CMTX) (Sarpota et al., 2011). The incidence of CMT1 is high when there is a comparison to that of CMT2, a situation, which experts link to the unidentified causal genes for CMT2. In addition, the difference in emergence of the disorder is primarily because of the variable phenotypes present in CMT, which results to substantial overlapping. Moreover, the mutations present the numerous varied genes generate a similar phenotype, subsequently, mutations present in similar genes will result to generation of different phenotypes.

For this reason, together with the large number of genes, the overall diagnosis and genetic counseling becomes a serious challenge for health practitioners. However, not all is lost because a molecular diagnosis is useful in guiding prognosis. In addition, the 45 and above genes and their proteins comprise of essential molecules, which play an imperative role in the normal performance of mylienated axons found in the peripheral nervous system (PNS). The significance of this is that when investigators mutate the proteins together with the genes, they can pave way for pathogenesis of the CMT disorder (Sarpota et al., 2011).

Currently, there have been successful clinical trials for several CMT types such as CMT1A, suggesting that it is possible to develop an accurate genetic diagnosis. Sarpota et al. (2001) suggests that clinical and neurophysiologic data is useful before choosing a genetic testing for CMT. This is because the information...

Although there are several algorithms developed in an attempt to establish an effective way to test for CMT, the author emphasizes that the above information will help in improving the results for genetic testing.
A typical example is the testing for CMT1X; for this, it is important to first ascertain the family history, especially that of male-to-male. If the test produces negative results, the testing should continue further. Although not every patient with a genetic neuropathy seeks to establish the genetic cause of their disease, the main reason should be to take the tests if a symptomatic child is still not 18 years of age. Nevertheless, genetic testing is expensive, and there is no cure for the neuropathy disorder, some aspects that make people refrain from the practice. It is possible for patients with these disorders to serve as their own models primarily after careful evaluation of their phenotypes and characterization of their genotypes.

Owing to this, experts can develop therapies for both CMT, and other hereditary neuropathies. The emerging treatment techniques for CMT include surgery, physical and occupational therapies, utilization of ambulation aids, but there is no known cure for CMT. Nevertheless, Murphy et al. (2012) suggests that molecular diagnosis will generate substantial results in 60% of patients with CMT. It is more achievable for CMT1 as compared to CMT2, mainly because the latter has many unknown causal genes. Notably, the above-mentioned four genes are responsible for 90% of all the CMT molecular diagnoses; therefore, patients who lack mutations in the four dominant genes should consult further assistance to receive exceptional care (Murphy et al., 2012).

Methods

Molecular diagnosis has made it possible to investigate variation in the human. This practical aims to utilize some of the diagnosis techniques to isolate and amplify a region of the human mitochondrial DNA, by the polymerase chain reaction (PCR). Students will digest their PCR product and analyze the sizes of the resulting fragments using gel electrophoresis.

Results

A

B

C

Figure one Detection of a HaeIII polymorphism in human DNA samples

A

In A, there are two ladders, and four lanes. In the digested products, we have two strands, one strand in the uncut products, and C. A positive for PCR negative control, and another single strand in the DNA sample. This is almost the similar case, applying in sample B. In this sample, we have two strands in the undigested products. The two strands suggest the existence of heterozygous alleles, which are weak, and the enzyme cannot cut the products in this sample. In addition, we also have a strand in N, which supports that there was no enzyme activity, hence the sample B. did not test positive for presence of a human DNA sample.

B

In sample B, there are three visible strands in the digested products, one in the uncut products, and a single strand in the DNA sample, and C. A positive for PCR negative control. However, this sample has one ladder, and three lanes. The three strands in the digested products, in this sample, suggest weakness hence the HaeIII could not cut it; this suggests that there was absence of a human DNA sample. In addition, the strand in N. is very visible, which further supports that the enzyme did not cut the products in this sample, further supporting that a human DNA sample was absent.

C

In the DNA sample C, we have four lanes and have two laddersIn the other four lanes, we do not have any visible strand. We have no strand in the undigested products, uncut products, and in the digested products. In addition, the lack of a strand in C, suggests that this sample tested positive for PCR, implying that there was enzyme activity. This sample tested positive for the presence of a human DNA sample.

Results

The study comprised of three samples namely A, B and C. however, the two samples, A and B, were control samples. A was a control DNA sample lacking the polymorphic site, whereas B. was a control DNA sample containing the polymorphic site. The sample C. was the one utilized by this study because it was the DNA sample for typing. In each lane, we have M, the size marker, D, digested product, N, uncut product, C, PCR negative control and DNA containing the DNA sample. PCR-RFLP methods were used in this study to determine polymorphism of human DNA samples. Something important to note is the term "ladders." This represents the solution of DNA molecules used in gel electrophoresis.

The ladder guides a person in comparing the bands on the inside to the ladder to approximate the lengths of the strands in each band. The DNA samples…