| The Neuromuscular Division Research Laboratory is using a comprehensive approach to tackle neuromuscular disorders at their molecular levels.
In 1991 Teepu Siddique, MD joined Northwestern as the Director of what was then the Neuromuscular Disorders Program and the research program has grown exponentially ever since.
We have a Neurologic Diseases Registry that contains human blood and tissue samples, medical, life and family history information, so that these carefully maintained materials are available for study. The Registry is the source for materials used in our individual projects. We also maintain a colony of animals with various forms of neurogenetic conditions for study.
We are have active projects exploring the roles of genetics in ALS and related disorders, such as PLS, the relationship between certain genes and biological and chemical detoxification in sporadic ALS, disease producing mechanisms in genetic forms of ALS and related disorders, the functions of proteins and drug screening, and the use of skin cells as sources of motor neuron producing induced pluripotent stem cells.
We combine expertise in bioinformatics, genetic counseling and advanced molecular biology techniques, with our Registry resources and state-of the art equipment in our sustained efforts to understand and develop treatments for neuromuscular disorders. |  |
Bioinformatics is a discipline that combines computer science and information technology to help us understand biological processes. It uses techniques such as pattern recognition, data mining, machine learning algorithms, and visualization). It can be helpful with many tasks including gene finding, sequence alignment, genome assembly, drug design, drug discovery, protein structure alignment, protein structure prediction, prediction of gene expression and protein-protein interactions and genome-wide association studies.
Genes function in complex ways with multiple interactions and effects. Most traditional methods in molecular biology explore disease a single gene at at time. This approach is limited, making it difficult to determine these interactions and effects. In the last several years DNA microarray technology, in which thousands of genes are implanted onto one single chip, has become a powerful tool for measuring expression levels of different genes. Genes with different expression levels in people with and without a disease are critical in the study of that disease. This tool allows researchers to figure out interactions occurring simultaneously within the entire genome. We are using Afymetrix Murine Genome chips to study SOD1 knock-out and wild type mice. Different software packages, including Spotfire, BRB-arrays and Chips, are used to analyze data from these chips. Genes identified statistically as different are clustered into groups so further biological experiments may be done to confirm the findings.
We are working to determine the functions of DNA and RNA in neuromuscular disorders using multiple algorithms and pipelinesusing with in-depth sequencing equipment.
Linkage analysis is performed using DNA samples from larger families with inherited or familial ALS (FALS) and other familial neuromuscular disorders in order to determine genes that cause the disease. The chromosomes are analyzed region by region and once a LOD score greater than 3 is identified, we narrow down that region of interest by using known markers along the chromosome. The goal is to narrow the region to a manageable number of genes which can then be screened for segregation of mutations in affected individuals.
Bioinformatics for Linkage Analysis Linkage analysis is a technique used to track the inheritance pattern of genetic markers with the inheritance pattern of a disease or trait. DNA samples collected from patients and their family members are examined to identify these co-segregated loci. The inheritance pattern of a trait may fit in a specific model or may not (model free). The former is a statistically more powerful tool under a correctly specified model and is most informative using large pedigrees, with multiply affected members. The latter is more powerful when the mode of inheritance is unknown, as in complex trait analysis using small pedigrees. Disease linkage to a specific chromosome locus can be determined with conventional microsatellite markers and newly discovered single nucleotide polymorphisms (SNPs). We use an advanced SNP genotyping system in which several thousand to well over one million genotypes can be processed within one day. Currently these linkage studies are being done in cooperation with the University of Miami and Vanderbilt University. Several loci have been identified for further confirmation and study.The gene ALSIN has been identified as the cause of a subset of juvenile onset familial ALS. ALSIN has some portions related to small GTP-ases, but its function is still unknown. To explore ALSIN function, we have analyzed proteins with which it interacts using a two-hybrid system. Using this method and a library of fetal brain clones, we have identified fifty proteins that interact with ALSIN. Now we are trying to verify those interactions using yeast cultures and immuno-histological methods to detect intercellular co-localization and co-immuno-precipitation. We have also designed and developed several ALSIN antibodies from both rabbit and chicken hosts. Through a series of Western blot and immuno-precipitation experiments using both human and mouse tissues of different types, we have identified one chicken and two rabbit ALSIN antibodies that work well with our recombinant ALSIN protein. We will use these significant antibodies to reveal characteristics of ALSIN protein and its proteins interactions.
Preliminary analysis in our lab have identified interesting region being the region of chromosome where sporadic ALS segregates with high probability. This preliminary evidence suggests that there is a genetic influence on this chromosome for ALS. Knowledge of the genetic alteration in the region of interest leads to knowledge what mutant protein can cause ALS. Our lab. is well equipped to tackle this task. All methods together: genetic, molecular biology, cell biology will provide the identification of both ALS genes and ALS modifier genes to allow the creation of new models for study.
A major focus of our work is human genetic studies. One type of study used to determine the location of a gene on a particular chromosome that causes an inherited disease is called "linkage analysis." Linkage studies involve collecting blood samples from both healthy and affected family members. DNA in the samples is then studied using genetic markers to pinpoint an area on a chromosome where the disease gene may lie. Once such an area is found, additional families are studied to help narrow the region until a single gene can be identified. Other techniques, such as disequilibrium analyses, are used to indentify genes that may increase risk for developing a particular disease. Isolated cases (sporadic cases) of a disease most likely occur as the result of interactions between a combination of genetic factors which increase risk and contact with particular environmental factors. The particular genetic background provides a threshold of vulnerability and contact with particular environmental factors then provide the push that causes disease to develop.
In some families, patients suffer from both Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD). Along with others, we have demonstrated linkage of ALS/FTD to chromosome 9q21-22. We plan to identify the causative gene in this region using molecular techniques such as DNA sequencing to better understand how ALS/FTD develops and the association between ALS and FTD in these cases. We are collecting and screening additional ALS/FTD families for linkage to 9q21-22 and for additional candidate genes.
To narrow down the region of 9q21-22, statistical assessments for linkage and heterogeneity will be performed as well as studying all candidate genes in the region. We focus on any gene with nucleotide variation that co-segregates with the disease but is not present in the general population. Once a causative gene is identified for FTD/ALS, information can be gathered on the pathogenesis of disease by studies of the gene, its protein, and transgenic mice. It will help us understand the relationship between ALS and FTD caused by that gene. We are collecting and screening additional ALS/FTD families for linkage to 9q21-22, as well as working to find the locations of other genes that cause ALS/FTD, but that is not linked to chromosome 9.
Sporadic ALS (SALS) is a complex disorder, most likely with multiple genes interacting with environmental influences to cause symptoms. A specific type of genomic study, called an association study, focuses on the influences of suspected genes. Our laboratory is undertaking these studies in SALS. These studies use relatives of the person with ALS, such as siblings and parents, to calculate specific ratios, to determine whether the gene in question is more/less likely to cause the patient’s ALS. Genes may predispose one to the disease by influencing either the onset or duration. Our laboratory holds the largest number of families in the world being used for these association studies and more of these genes are likely to be identified by our research team.
Alsin is a cause of juvenile type of familial ALS. Alsin gene has some domain related small GTPase, but it function is still unknown. To elucidate Alsin function, we analyze the Alsin interaction protein to use the two-hybrid method. Use this method, we get fifty positive clones related Alsin from a library of fetal brain clones. Now we are retesting the protein interaction using to switch the yeast, and immuno-histological method to detect intercellular co-localization, and co-immuno-precipitation.
Our Bank contains the blood samples, DNA, lymphoblast cell lines, skin samples and fibroblasts, induced pluripotent stem cells (IPSCs) and brain and spinal cord tissue essential for our research. Blood samples from participating patients, their family members and neurologically normal controls are used for DNA extraction and white cell transformation into cell lines, which provide ongoing sources of DNA. Red cells and plasma are also stored. We have more than 7000 lymphoblast cell lines and 10,000 DNA samples. These collections have been used successfully to map genes associated with familial ALS, recessive juvenile ALS, PLS and other neurodegenerative diseases. Our newest exciting collection is patient skin samples which are used to make pluripotent stem cells, which, in turn can generate neurons. Our brain tissue and spinal cord tissue from patients with all types of ALS, as well as related disorders are preserved for research into pathological and genetic investigations. For blood sample donation and skin sample donation please contact Sandra Donkervoort, MS CGC at 312-503-0154 or s-donkervoort@northwestern.edu or Nailah Siddique RN MSN at 312-50302712 or nsiddique@northwestern.edu. Unfortunately we are unable to accept brain and spinal cord donations at this time.
Symptoms are weakness and atrophy of the muscles of the hands and lower legs, with foot deformities and some loss of sensation in the feet. Onset occurs in childhood to early adulthood with progression being slow but variable and not affecting life expectancy. Inheritance is autosomal dominant, autosomal recessive, and X-linked recessive. (Read more about CMT)
Symptoms are similar to CMT, however more severe with delayed motor development in childhood, weakness and muscle wasting of the hands and lower legs, and some loss of sensation in the feet. Onset ranges from early childhood with progression being variable. Inheritance is believed to be autosomal dominant (Read more about Dejerine Sottas Disease)
Symptoms are impairment of limb coordination with weakness, muscle wasting, and sometimes diabetes and heart disease. Onset ranges from childhood to adolescence with progression and severity varying. Inheritance is autosomal recessive. (Read more about Freidreich's Ataxia)
Symptoms of generalized muscle weakness and muscle wasting affecting limb and trunk muscles first with enlarged calves. The disease progresses slowly, with an onset about 2-6 years. Survival is rarely beyond late twenties. Inheritance is X-linked recessive. (Read more about DMD)
Symptoms are almost identical to Duchenne muscular dystrophy with regards to the muscle weakness and wasting, but is often much less severe. There can be significant heart involvement. The disease progresses slowly, with an onset in adolescence or adulthood, with survival well into mid to late adulthood. Inheritance is X-linked recessive. (Read more about BMD)
Symptoms are weakness and wasting of the shoulder, upper arms, and shin muscles with possible joint deformities. Cardiac involvement is common. The disease progresses slowly, with an onset in childhood to early teens. Inheritance is X-linked recessive the majority of the time. (Read more about EDMD)
Symptoms are weakness and wasting affecting shoulder and pelvic girdle muscles. Cardiopulmonary complications occur in later stages of the disease. The disease progresses slowly with onset in childhood to middle age. Inheritance is autosomal recessive or X-linked. (Read more about LGMD)
Symptoms are facial muscle weakness and wasting of the shoulders and upper arms. The disease progresses slowly with some periods of rapid deterioration with onset in childhood to early adulthood. The disease may span many decades. Inheritance is autosomal dominant. (Read more about FSHD)
Symptoms are generalized weakness and muscle wasting affecting the face, hands, feet and neck. People experience delayed relaxation of muscles after contraction. Progression is slow with onset in childhood to middle age, however there are some forms of congenital myotonic dystrophy that can be more severe. Inheritance is autosomal dominant. (Read more about DM)
Symptoms occur as weakness of the in the muscles of the eyelid and throat. Progression is slow and swallowing problems are common as the disease progresses; onset is early adulthood to middle age. Inheritance is autosomal dominant. (Read more about OPMD)
Symptoms are weakness and wasting of muscles of the hands, forearms, and lower legs. Onset is between 40 to 60 years. It progresses slowly and is not life threatening. Inheritance is autosomal dominant. (Read more about DD)
Symptoms are generalized muscle weakness with possible joint deformities. Progression is very slow but onsets at birth. Inheritance is autosomal dominant and autosomal recessive. (Read more about CMD)
Symptoms are weakness of the upper arm and upper leg muscles with some muscle wasting. Onset ranges from childhood to adulthood with progression and symptoms improving with treatment of the underlying thyroid condition. (Read more about Hyperthyroid Myopathy)
Symptoms are weakness of farm and leg muscles with stiffness and muscle cramping. Onset ranges from childhood to adulthood with progression and symptoms improving with treatment of the underlying thyroid condition. (Read more about Hypothyroid Myopathy)
Symptoms are weakness of neck and limb muscles; muscle pain; and sometimes associated with malignancy. Onset ranges from childhood to late adulthood with progression and severity varying as well. This disease can respond to drug therapy. (Read more about Polymyositis)
Symptoms are weakness of the neck and limb muscles, muscle pain, and skin rashes affecting the cheeks, eyelids, neck, chest, and limbs. Onset ranges from childhood to late adulthood with progression and severity varying as well. This disease can respond to drug therapy. (Read more about Dermatomyositis)
Symptoms are weakness of arms, legs, hands, especially the thighs, wrists, and fingers. Onset is typically after 50 years with progression being slow. ( Read more about IBM)
Symptoms are generalized weakness and muscle wasting with muscle twitches. Onset is in adulthood and progression is rapid, with the average survival being 3-5 years. ALS is usually sporadic, with some cases having autosomal dominant or autosomal recessive inheritance. (Read more about ALS)
Symptoms are generalized muscle weakness, weak cry, difficulty swallowing and sucking, and respiratory problems. Onset is between birth and 3 months with rapid progression leading to early childhood death. Inheritance is autosomal recessive. (Read more about SMA)
Symptoms are weakness in arms, legs, and upper and lower torso. Onset is between 6-12 months with progression varying according to the extent of respiratory involvement. Inheritance is autosomal recessive. (Read more about SMA)
Symptoms are weakness in leg, hip, shoulder, arm, and sometimes respiratory muscles. Onset is between 13 months and adolescence with slow progression and no effect on lifespan. Inheritance is autosomal recessive. (Read more about SMA)
Symptoms are generalized weakness and muscle wasting with muscle twitching. Onset is over 18 years into adulthood with variable progression and normal life expectancy. Inheritance is autosomal recessive. (Read more about SMA)>
Symptoms are weakness and muscle wasting of the bulbar muscles (throat and mouth) and skeletal muscles. Facial and muscle jumping is common; breast development, infertility and testicular wasting can occur. It usually affects only men. Females are carriers who are usually asymptomatic or have a mild form. Onset is adulthood with progression being slow and variable with normal lifespan. Inheritance is X-linked recessive. (Read more about SBMA)
Symptoms are muscle stiffness and cramps usually occurring after periods of rest; however muscle function returns to normal with activity. Onset ranges from infancy to childhood with the disease causing discomfort but normal life-expectancy. Inheritance is autosomal dominant and autosomal recessive. (Read more about Mytonia Congenita)
Symptoms are poor or difficult relaxation of muscles which may worsen after repeated use or exercise and is often associated with hyperkalemic periodic paralysis. Onset is childhood to early adulthood with the disease causing discomfort but normal life-expectancy. Inheritance is autosomal dominant. (Read more about Paramyotonia Congenita)
Symptoms are delayed motor development with possible hip dislocation at birth. Onset is early infancy to childhood with progression varying such that it may be disabling. Inheritance is autosomal dominant. (Read more about Central Core Disease)
Symptoms are delayed motor development with weakness of arms, legs, trunk, face, and throat muscles. Onset is in early childhood with progression varying and may be life-threatening. Inheritance is autosomal dominant or autosomal recessive. (Read more about Nemaline Myopathy)
Symptoms are drooping of upper eyelids, facial weakness, blackout spells, weakness of the limbs and trunk muscles, and absent reflexes. Onset is infancy with slow progression. Inheritance is X-linked recessive, autosomal recessive, or autosomal dominant. (Read more about Myotubular Myopathy)
Symptoms are episodes of generalized muscle weakness with periods of paralysis affecting arms, legs, and neck. Onset ranges from childhood to adulthood with varying frequency of the attacks. These diseases may respond to drug therapy. Inheritance is autosomal dominant. (Read more about Periodic Paralysis)
Symptoms are weakness and fatigability of the muscles of the eyes, fact, neck, throat, limbs, and/or trunk. Onset ranges from childhood to adulthood with progression varying. This disease can respond to drug therapy or removal of the thymus gland as an effective treatment. ( Read more about MG)
Symptoms include weakness and fatigue of the hip muscles with aching back and thigh muscles common; sometimes associated with lung tumors. Onset is typically during adulthood with progression varying based on the success of drug therapy and treatment of malignancy. (Read more about Lambert-Eaton Syndrome)
Symptoms are generalized weakness and fatigability of voluntary muscles including those that control mobility, eye movement, swallowing, and breathing. Onset is infancy or childhood, however can be later, with progression varying in severity. ( Read more about CMS)
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