Name: genetic analysis of hereditary transthyretin ala97ser related amyloidosis
Uploaded: 2018-06-09T15:00:00
Description: Watch this Scientific Journal Video about Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis at JoVE.com

We wish to thank Miss Shin-Fun Wu for her help in the experiments. This study was supported by a grant from the Chang Gung Medical Research Program (CMRPG3C0371, CMRPG3C0372, CMRPG3C0373) and IRB 100-4470A3, 104-2462A3, Taiwan.

The testing performed in the laboratory was carried out in accordance with the requirements of the Clinical Laboratory Improvement Amendments (CLIA) of 1988, the regulations approved by the Institutional Review Board of Chang Gung Memorial Hospital and University (License no. 100-4470A3 and 104-2462A3). Informed consent was obtained from all patients.
1. Blood Specimen Collection
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	<li>Collect whole blood into commercially available EDTA-treated tubes. Mix gently and store blood sample a...

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	<li>Plant&#233;-Bordeneuve, V., Said, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Familial+amyloid+polyneuropathy.">Familial amyloid polyneuropathy.</a> The Lancet Neurology. 10 (12), 1086-1097 (2011).</li><li>Plant&#233;-Bordeneuve, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+treatment+of+transthyretin+familial+amyloid+polyneuropathy+with+tafamidis:+a+clinical+and+neurophysiological+study.">Long-term treatment of transthyretin familial amyloid polyneuropathy with tafamidis: a clinical and neurophysiological study.</a> Journal of Neurology. 264 (2), 268-276 (2017).</li><li>Nichols, W. C., Benson, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hereditary+amyloidosis:+detection+of+variant+prealbumin+genes+by+restriction+enzyme+analysis+of+amplified+genomic+DNA+sequences.">Hereditary amyloidosis: detection of variant prealbumin genes by restriction enzyme analysis of amplified genomic DNA sequences.</a> Clinical Genetics. 37 (1), 44-53 (1990).</li><li>Lorenz, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymerase+Chain+Reaction:+Basic+Protocol+Plus+Troubleshooting+and+Optimization+Strategies.">Polymerase Chain Reaction: Basic Protocol Plus Troubleshooting and Optimization Strategies.</a> Journal of Visualized Experiments. (63), e3998 (2012).</li><li>Hsu, H. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phenotypic+expressions+of+hereditary+Transthyretin+Ala97Ser+related+Amyloidosis+(ATTR)+in+Taiwanese.">Phenotypic expressions of hereditary Transthyretin Ala97Ser related Amyloidosis (ATTR) in Taiwanese.</a> BMC Neurology. 17 (1), 178 (2017).</li><li>Barroso, F. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+safety+and+efficacy+of+tafamidis+for+the+treatment+of+hereditary+transthyretin+amyloid+polyneuropathy:+results+up+to+6+years.">Long-term safety and efficacy of tafamidis for the treatment of hereditary transthyretin amyloid polyneuropathy: results up to 6 years.</a> Amyloid. 24 (3), 194-204 (2017).</li><li>Rapezzi, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disease+profile+and+differential+diagnosis+of+hereditary+transthyretin-related+amyloidosis+with+exclusively+cardiac+phenotype:+an+Italian+perspective.">Disease profile and differential diagnosis of hereditary transthyretin-related amyloidosis with exclusively cardiac phenotype: an Italian perspective.</a> European Heart Journal. 34 (7), 520-528 (2013).</li><li>Mariani, L. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genotype-phenotype+correlation+and+course+of+transthyretin+familial+amyloid+polyneuropathies+in+France.">Genotype-phenotype correlation and course of transthyretin familial amyloid polyneuropathies in France.</a> Annals of Neurology. 78 (6), 901-916 (2015).</li><li>Hammarstr&#246;m, P., Jiang, X., Hurshman, A. R., Powers, E. T., Kelly, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequence-dependent+denaturation+energetics:+A+major+determinant+in+amyloid+disease+diversity.">Sequence-dependent denaturation energetics: A major determinant in amyloid disease diversity.</a> Proceedings of the National Academy of Sciences of the United States of America. 99, 16427-16432 (2002).</li><li>Johnson, M., Zaretskaya, I., Raytselis, Y., Merezhuk, Y., McGinnis, S., Madden, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NCBI+BLAST:+a+better+web+interface.">NCBI BLAST: a better web interface.</a> Nucleic Acids Research. 36, 5-9 (2008).</li><li>Fox, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Next+generation+sequencing+for+the+detection+of+actionable+mutations+in+solid+and+liquid+tumors.">Next generation sequencing for the detection of actionable mutations in solid and liquid tumors.</a> Journal of Visualized Experiments. (115), (2016).</li><li>Date, Y., Nakazato, M., Kangawa, K., Shirieda, K., Fujimoto, T., Matsukura, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+three+transthyretin+gene+mutations+in+familial+amyloidotic+polyneuropathy+by+analysis+of+DNA+extracted+from+formalin-fixed+and+paraffin-embedded+tissues.">Detection of three transthyretin gene mutations in familial amyloidotic polyneuropathy by analysis of DNA extracted from formalin-fixed and paraffin-embedded tissues.</a> Journal of the Neurological Sciences. 150 (2), 143-148 (1997).</li><li>Ye, J., Coulouris, G., Zaretskaya, I., Cutcutache, I., Rozen, S., Madden, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primer-BLAST:+a+tool+to+design+target-specific+primers+for+polymerase+chain+reaction.">Primer-BLAST: a tool to design target-specific primers for polymerase chain reaction.</a> BMC Bioinformatics. 13, 134 (2012).</li><li>Green, M. R., Sambrook, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Molecular cloning: A laboratory manual. , (2012).</li><li>Buckingham, L., Flaws, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Molecular diagnostics: Fundamentals, methods, and clinical applications. , (2012).</li><li>Tan, S. C., Yiap, B. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA,+RNA,+and+Protein+Extraction:+The+Past+and+The+Present.">DNA, RNA, and Protein Extraction: The Past and The Present.</a> Journal of Biomedicine and Biotechnology. 2009, (2009).</li><li>Rapezzi, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systemic+cardiac+amyloidoses:+disease+profiles+and+clinical+courses+of+the+3+main+types.">Systemic cardiac amyloidoses: disease profiles and clinical courses of the 3 main types.</a> Circulation. 120 (13), 1203-1212 (2009).</li><li>Gertz, M. A., Dispenzieri, A., Sher, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathophysiology+and+treatment+of+cardiac+amyloidosis.">Pathophysiology and treatment of cardiac amyloidosis.</a> Nature Reviews Cardiology. 12 (2), 91-102 (2015).</li><li>Vrana, J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+diagnosis+and+typing+of+systemic+amyloidosis+in+subcutaneous+fat+aspirates+by+mass+spectrometry-based+proteomics.">Clinical diagnosis and typing of systemic amyloidosis in subcutaneous fat aspirates by mass spectrometry-based proteomics.</a> Haematologica. 99 (7), 1239-1247 (2014).</li><li>Nakamura, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+new+transthyretin+variant+(Ile49)+in+familial+amyloidotic+polyneuropathy+using+electrospray+ionization+mass+spectrometry+and+nonisotopic+RNase+cleavage+assay.">Identification of a new transthyretin variant (Ile49) in familial amyloidotic polyneuropathy using electrospray ionization mass spectrometry and nonisotopic RNase cleavage assay.</a> Human Heredity. 49 (4), 186-189 (1999).</li><li>Ueda, M., Ando, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+transthyretin+amyloidosis+therapy.">Recent advances in transthyretin amyloidosis therapy.</a> Translational Neurodegeneration. 3, 19 (2014).</li><li>Brown, E. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+testing+improves+identification+of+transthyretin+amyloid+(ATTR)+subtype+in+cardiac+amyloidosis.">Genetic testing improves identification of transthyretin amyloid (ATTR) subtype in cardiac amyloidosis.</a> Amyloid. 24 (2), 92-95 (2017).</li><li>Tasaki, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+detection+of+wild-type+and+mutated+transthyretins.">Rapid detection of wild-type and mutated transthyretins.</a> Annals of Clinical Biochemistry. 53 (4), 508-510 (2015).</li><li>Plante-Bordeneuve, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnostic+pitfalls+in+sporadic+transthyretin+familial+amyloid+polyneuropathy+(TTR-FAP).">Diagnostic pitfalls in sporadic transthyretin familial amyloid polyneuropathy (TTR-FAP).</a> Neurology. 69 (7), 693-698 (2007).</li><li>Hsu, J. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+prospective,+observational+study+of+patients+with+uncommon+distal+symmetric+painful+small-fiber+neuropathy.">A prospective, observational study of patients with uncommon distal symmetric painful small-fiber neuropathy.</a> PLoS ONE. 12 (9), 0183948 (2017).</li><li>Salvi, F., Pastorelli, F., Plasmati, R., Bartolomei, I., Dall'Osso, D., Rapezzi, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genotypic+and+phenotypic+correlation+in+an+Italian+population+of+hereditary+amyloidosis+TTR-related+(HA-TTR):+Clinical+and+neurophysiological+aids+to+diagnosis+and+some+reflections+on+misdiagnosis.">Genotypic and phenotypic correlation in an Italian population of hereditary amyloidosis TTR-related (HA-TTR): Clinical and neurophysiological aids to diagnosis and some reflections on misdiagnosis.</a> Amyloid. 19, 58-60 (2012).</li><li>Suhr, O. B., Lundgren, E., Westermark, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One+mutation,+two+distinct+disease+variants:+Unravelling+the+impact+of+transthyretin+amyloid+fibril+composition.">One mutation, two distinct disease variants: Unravelling the impact of transthyretin amyloid fibril composition.</a> Journal of Internal Medicine. 281 (4), 337-347 (2017).</li><li>Vil&#224;-Rico, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+analysis+of+post-translational+modifications+in+human+serum+transthyretin+associated+with+familial+amyloidotic+polyneuropathy+by+targeted+LC-MS+and+intact+protein+MS.">Quantitative analysis of post-translational modifications in human serum transthyretin associated with familial amyloidotic polyneuropathy by targeted LC-MS and intact protein MS.</a> Journal of Proteomics. 127, 234-246 (2015).</li></ol>

There are two critical steps within the protocol. First, in order to have sufficient number of white blood cells, a hemodiluted specimen should be avoided11. Second, the use of appropriate PCR primers is fundamental to obtain reliable results12. We used the Primer-BLAST web tool to design the primers4,13; a minimum of 40 base pairs on each side of the four TTR exons should be covered. We also run BLAST on NCBI to ch...

Transthyretin (TTR) amyloidosis (ATTR) is the most common form of hereditary systemic amyloidosis1, and can be caused by an autosomal dominantly inherited mutation in the transthyretin (TTR) gene2. TTR mutations destabilize the tetrameric protein structure and lead to its dissociation into monomers that reassembles into amyloid fibrils2. More than 100 amyloidogenic TTR mutations have been reported worldwide1. Genetic analyses with polymerase chain reaction (PCR) methods confirm the presence of TTR point mutation and have advantages including avoiding the handling of radioactively labeled probes in comparison with southern blot3. PCR is a&#160;fast, easy, cheap, and reliable technique that has been applied to numerous fields in modern sciences4.
The early diagnosis of this progressive and fatal disease is challenging given its phenotypic heterogeneity. With increasing attention and broader recognition on the early manifestations of ATTR as well as the emerging treatments5, appropriate diagnostic studies including TTR genetic test are therefore critically fundamental to improve prognosis. Furthermore, different mutations are associated with different penetrance of the trait, age of onset, patterns of progression, disease severity, median survival, efficacy of liver transplantation, or TTR stabilizers2,6, and variable degrees of neurological and cardiological involvement, which have great implications for genetic counseling7,8,9. Besides, a highly accurate genetic test is the only tool that differentiates the two distinct types of ATTR: hereditary (mutant) and wild type (non-mutant form, senile systemic amyloidosis, SSA)7. It is imperative to confirm the types of ATTR, because the therapies vary widely2. Therefore, there is an increasing necessity to describe the stepwise protocol of the TTR genetic test.
The molecular approach to detect the mutation will be illustrated using Ala97Ser, the most common endemic mutation in Taiwan, as an example. Modifications in the DNA extraction step reduce the amount of the three solutions used and yields a sufficient amount of DNA. In this protocol, all four TTR exons were analyzed, while regions including 5&#39; upstream, 3&#39; downstream, promoters, introns, and untranslated regions (UTR) were not sequenced.

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			<td height="21" style="height:21px;width:213px;">EDTA-treated tubes</td>
			<td style="width:199px;">BD</td>
			<td style="width:347px;"></td>
			<td style="width:192px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;">DNA Extraction Kit</td>
			<td style="width:199px;">Stratagen</td>
			<td style="width:347px;">200600</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:213px;">NanoDrop ND2000 spectrophotometer&#160;</td>
			<td style="width:199px;">Thermo Fisher Scientific</td>
			<td style="width:347px;">NanoDrop 2000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;">Delicate Task Wipers</td>
			<td style="width:199px;">Kimberly-Clark</td>
			<td style="width:347px;">Kimtech Science Kimwipes</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:213px;">AmpliTaq Gold 360 DNA Polymerase kit</td>
			<td style="width:199px;">Applied Biosystems</td>
			<td style="width:347px;">4398823</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;">TTR gene intronic primers&#160;</td>
			<td style="width:199px;">Exon1</td>
			<td style="width:347px;">F: 5&#8217;-TCAGATTGGCAGGGATAAGC-3&#8217;</td>
			<td></td>
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			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon1</td>
			<td style="width:347px;">R: 5&#8217;-GCAAAGCTGGAAGGAGTCAC-3&#8217;</td>
			<td></td>
		</tr>
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			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon2</td>
			<td style="width:347px;">F: 5&#8217;-TCTTGTTTCGCTCCAGATTTC-3&#8217;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon2</td>
			<td style="width:347px;">R: 5&#8217;-TCTACCAAGTGAGGGGCAAA-3&#8217;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon3</td>
			<td style="width:347px;">F: 5&#8217;-GTGTTAGTTGGTGGGGGTGT-3&#8217;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon3</td>
			<td style="width:347px;">R: 5&#8217;-TGAGTAAAACTGTGCATTTCCTG-3&#8217;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon4</td>
			<td style="width:347px;">F: 5&#8217;-GACTTCCGGTGGTCAGTCAT-3&#8217;</td>
			<td></td>
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			<td height="21" style="height:21px;width:213px;"></td>
			<td style="width:199px;">Exon4</td>
			<td style="width:347px;">R: 5&#8217;-GCGTTCTGCCCAGATACTTT-3&#8217;</td>
			<td></td>
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			<td height="21" style="height:21px;width:213px;">thermocycler</td>
			<td style="width:199px;">Applied Biosystems</td>
			<td style="width:347px;">GeneAmp PCR System 9700</td>
			<td></td>
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			<td height="21" style="height:21px;width:213px;">electrophoresis cell&#160;</td>
			<td style="width:199px;">ADVANCE</td>
			<td style="width:347px;">Mupid-2plus</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;">DNA ladder</td>
			<td style="width:199px;">Protech</td>
			<td style="width:347px;">PT-M1-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;">dye</td>
			<td style="width:199px;">BioLabs</td>
			<td style="width:347px;">B7021</td>
			<td></td>
		</tr>
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			<td height="21" style="height:21px;width:213px;">AlphaImager EC</td>
			<td style="width:199px;">Alpha Innotech</td>
			<td style="width:347px;">AlphaImager EC</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:213px;">automatic sequencer&#160;</td>
			<td style="width:199px;">Applied Biosystems</td>
			<td style="width:347px;">3730xl DNA Analyzer</td>
			<td></td>
		</tr>
	</tbody>
</table>

genetic analysis of hereditary transthyretin ala97ser related amyloidosis

Genetic testing is the most reliable test for hereditary transthyretin related amyloidosis and should be performed in most cases of transthyretin amyloidosis (ATTR). ATTR is a rare but fatal disease with heterogeneous phenotypes; therefore, the diagnosis is sometimes delayed. With increasing attention and broader recognition on early manifestations of ATTR as well as emerging treatments, appropriate diagnostic studies, including the transthyretin (TTR) genetic test, to confirm the types and variants of ATTR are therefore fundamental to improve the prognosis. Genetic analyses with polymerase chain reaction (PCR) methods confirm the presence of TTR point mutations much more quickly and safer than conventional methods such as southern blot. Herein, we demonstrate genetic confirmation of the ATTR Ala97Ser mutation, the most common endemic mutation in Taiwan. The protocol comprises four main steps: collecting whole blood specimen, DNA extraction, genetic analysis of all four TTR exons with PCR, and DNA sequencing.

Agarose gel electrophoresis of two patients and one healthy individual revealed bands of the expected sizes, including a 454 bp PCR product for exon 4 of the TTR gene (Figure 1).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57743/57743fig1.jpg" /> 
Figure 1. Gel electrophoresis depicting PCR amplified TTR gene. Normal: a healthy indiv...

Watch this Scientific Journal Video about Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis at JoVE.com

Genetic Analysis of Hereditary Transthyretin Ala97Ser Related Amyloidosis

Here, we present a protocol to confirm the presence of point mutation for the diagnosis of hereditary transthyretin amyloidosis, using Ala97Ser, the most common endemic mutation in Taiwan, as an example.

Genetic testing is the most reliable test for hereditary transthyretin related amyloidosis and should be performed in most cases of transthyretin ...

With increasing attention on early manifestations of transthyretin amyloidosis as well as emerging treatments appropriate studies to confirm the types and variants of transthyretin amyloidosis are fundamental to improve prognosis. The main advantage of this protocol is that this test is feasible and easy to preform in the clinical laboratory. To begin the protocol obtain a DNA extraction kit, add 10 milliliters of solution one to the previous obtained 4.0 milliliter blood sample and incubate the sample on ice for 10 minutes.After incubation centrifuge the sample at 2000 G for five minutes at four degrees Celsius. Carefully remove and discard the supernatant. Re suspend the pellet in three milliliters of solution one.Centrifuge the sample at 2000 G for five minutes at four degrees Celsius again. Discard the supernatant. Re suspend the pellet in three milliliters of solution two.Next, add 10 microliters of Pronase stock solution to get a final concentration of 100 micrograms per milliliter and mix the contents well. Incubate the DNA at 37 degrees Celsius overnight. The next day, chill the tube on ice for 10 minutes.Add 0.8 milliliters of solution three to the sample and invert it three to five times. Then, place the sample on ice for five minutes. Centrifuge the sample at 3000 G for 15 minutes at four degrees Celsius.Carefully transfer the supernatant to a 15 milliliter sterile conical centrifuge tube and add six microliters of RNase stock solution to obtain a final concentration of 20 micrograms per milliliter. Incubate the sample, add 2.5 milliliters of isopropyl alcohol to the tube and gently invert the tube several times to precipitate the DNA which appears as strands of white flocculant material. With a large bore pipette transfer the precipitate to a new 1.5 milliliter centrifuge tube.Centrifuge the precipitate at 12, 000 G for three minutes at four degrees Celsius. Discard the supernatant carefully. Then wash the DNA pellet by adding 500 microliters of 70%ethanol.Centrifuge the DNA at 12, 000 G for one minute and discard the supernatant. Air dry the DNA pellet at room temperature. Add 100 microliters of DDH2O and incubate the sample at 65 degrees Celsius for 15 minutes to re suspend the DNA.Perform PCR in a 25 microliter reaction mixture using a DNA polymerase kit. Add the reagents to a 0.2 milliliter PCR tube. Mix the contents gently and briefly centrifuge them in a bench top centrifuge.Place the tube in a thermal cycler. Perform the PCR for 30 cycles with a denaturation step for 30 seconds at 94 degrees Celsius, primer enabling for 30 seconds at 58 degrees Celsius and polymerase extension for 45 seconds at 72 degrees Celsius. Prepare a 1.2%agarose gel by mixing 1.2 grams of agarose powder with 100 milliliters of 0.5 XTBE in a microwaveable flask.Microwave the solution for two minutes until the agarose is completely dissolved. Cool down the agarose mixture to 55 degrees Celsius. Add two microliters of ethidium bromide solution to the agarose mixture and mix gently.Pour the mixture into a gel tray to about five to seven millimeters. Then, insert the comb. Allow the gel to solidify for at least 30 minutes.After the gel has solidified carefully remove the comb. Place the gel and tray into the electrophoresis cell. Fill the electrophoresis cell with 0.5 XTBE until the gel is covered.Carefully load two microliters of a 100 base pair DNA ladder into the one lane of the gel as a molecular size marker. Load the dye and sample mixture into the additional lanes. Turn on the power supply and run the gel for 25 minutes at 100 volts.Remove the gel from the electrophoresis cell. Finally, visualize the DNA fragments under UV light in an imaging system. Agarose gel electrophoresis of two patients and one healthy individual reveal bands of the expected sizes including a 454 base pair PCR product for exon four of the TTR gene.Sequence chromatograms disclosed a nucleotide T substitution for G in exon four of the TTR gene resulting in a missense mutation and an alanine to serine substitution at amino acid position 97 in two patients. After watching this video you should have a good understanding of how to confirm the presence of point mutations for the diagnosis of hereditary transthyretin amyloidosis.

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