About Dhavendra Kumar

Since 1980 Professor Dhavendra Kumar has pursued a career in Genomic Medicine in the United Kingdom. In 1990 he became a Diplomate of the American Board of Medical Genetics. He is a Fellow of the American College of Medical Genetics (FACMG) and as well as Royal Colleges of Physicians of Ireland & London and The UK Royal College of Paediatrics & Child Health.

Molecular Basis of Developmental Anomalies of the Human Gastrointestinal Tract

Current knowledge of the etiology of congenital malformations of the human gastrointestinal tract is covered in this book, prefaced by some introductory notes on embryological development. Malformations involving the esophagus, stomach, small and large intestine, anus and rectum, pancreas, and hepato-billiary system are covered. There is a focus on covering those malformations for which a molecular genetic etiology is understood, but other causations, including environmental exposures, twinning, and unknown etiology are also included. For completeness, some disorders are included which are not, strictly, malformations, or which do not, strictly, involve the gastrointestinal tract. Such disorders include Hirschsprung disease, congenital diaphragmatic hernia, omphalocele, and gastroschisis. Suggested approaches to clinical evaluation of individuals with gastrointestinal malformations are included.

Molecular Genetics of Thalassemia Syndromes

This book reviews the molecular genetics of the thalassemia syndromes, inherited hemoglobin disorders that comprise the commonest monogenic disorders globally. Thalassemias are found in high frequencies in tropical regions corresponding to the malaria belt. Beta thalassemia traits show high HbA2 by HPLC, and β-globin mutations (commonly point mutations) are detected by using ARMS-PCR, reverse dot-blot analysis and β-globin gene sequencing. Globally >300 β globin gene mutations exist, however regional mutations are limited to 5-6 common ones. Alpha globin gene defects can only be identified by molecular tests, the exception being HbH disease that shows “golf ball” appearance in HbH preparation, pre-integration peaks on HPLC and a fast-moving band on hemoglobin electrophoresis. Multiplex Gap-PCR identifies common α-globin gene deletions. Specific PCR across the junction caused by the unequal crossing over can detect α-gene triplication. However, heterozygosity or homozygous triplication cannot be resolved by this technique. Non-deletional α-thalassemia can be characterized by specific α-globin gene sequencing. Identification of unusual deletions requires Multiplex Ligation-dependent Probe Amplification. In conclusion, the molecular characterization of human globin gene disorders is required to resolve the phenotypically heterogeneous thalassemia syndromes. Molecular analysis is also an important tool to prevent these disorders by offering prenatal screening in regions with a high disease burden.

Clinical and Molecular Heterogeneity of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a disease encompassing a group of disorders mainly characterized by bone fragility and is the commonest form of heritable bone fragility. In this book, the clinical presentations with particular emphasis on rare phenotypes associated with OI are discussed together with molecular advances in diagnosis and treatment of OI. There is a broad spectrum of clinical severity in OI, ranging from multiple fractures in utero and perinatal death, to near-normal adult stature and low fracture incidence. Facial dysmorphism has been noted, but is not well described, nor is it an invariable feature. Sillence et al., in 1979, provided the clinical classification, which has been further expanded. Genetic defects in type 1 collagen can be identified in 85% of patients with a clinical diagnosis of OI, that is, mutations in COL1A1/COL1A2, which follows an autosomal dominant pattern of inheritance. Several genes have now been implicated in autosomal recessive forms of OI and X-linked osteoporosis. Given the possible antenatal presentation and prognosis associated with OI, it is important to make this diagnosis early and be able to distinguish this from other lethal skeletal dysplasias. It is also important to distinguish nonaccidental injury from a pathological cause of fractures, such as OI, and diagnose this promptly in these situations. However, this is not always possible due to variability in presentation and inability to pinpoint the precise genetic etiology despite extensive genetic testing. OI is one such rare genetic condition where treatment is available in the form of bisphosphonates, which has a huge impact on quality of life. Despite advances in medical therapy, multidisciplinary management including physiotherapy remains the mainstay of treatment and improved outcomes in OI.

Medical and Health Genomics

Medical and Health Genomics provides concise and evidence-based technical and practical information on the applied and translational aspects of genome sciences and the technologies related to non-clinical medicine and public health. Coverage is based on evolving paradigms of genomic medicine―in particular, the relation to public and population health genomics now being rapidly incorporated in health management and administration, with further implications for clinical population and disease management.

  • Provides extensive coverage of the emergent field of health genomics and its huge relevance to healthcare management
  • Presents user-friendly language accompanied by explanatory diagrams, figures, and many references for further study
  • Covers the applied, but non-clinical, sciences across disease discovery, genetic analysis, genetic screening, and prevention and management
  • Details the impact of clinical genomics across a diverse array of public and community health issues, and within a variety of global healthcare systems

Genomics and Society

Genomics and Society; Ethical, Legal-Cultural, and Socioeconomic Implications is the first book to address the vast and thorny web of ELSI topics identified as core priorities of the NHGRI in 2011.

The work addresses fundamental issues of biosociety and bioeconomy as the revolution in biology moves from research lab to healthcare system.

Of particular interest to healthcare practitioners, bioethicists, and health economists, and of tangential interest to the gamut of applied social scientists investigating the societal impact of new medical paradigms, the work describes a myriad of issues around consent, confidentiality, rights, patenting, regulation, and legality in the new era of genomic medicine.

Genomic Medicine Principles and Practice

The first edition of Genomics and Clinical Medicine provided an overview of genomics-based advances in disease susceptibility, diagnosis, and prediction of treatment outcomes in various areas of medicine. Since its publication, the science of genomics has made tremendous progress, and exciting new developments in biotechnology and bioinformatics have created possibilities that were inconceivable only a few years ago. This completely revised second edition of Genomic Medicine reflects the rapidly changing face of applied and translational genomics in the medical and health context and provides a comprehensive coverage of principles of genetics and genomics relevant to the practice of medicine.

The Molecular Biology of Chronic Heart Failure

The clinical syndrome of chronic heart failure (CHF) is the hallmark of progressive cardiac decompensation, one of the most common chronic medical conditions that affect around 2% of the adult population worldwide irrespective of ethnic and geographic origin (Anonymous). Apart from ischemic heart disease, hypertension, infection, and inflammation, several other etiologic factors account for irreparable and irreversible myocardial damage leading to heart failure (HF). Genetic and genomic factors are now increasingly identified as one of the leading underlying factors (Arab and Liu 2005). These factors may be related to pathogenic alterations (mutation or polymorphism) within specific cardiac genes, mutations in genes incorporating single or multiple molecular pathways (protein families) relevant to cardiac structure and/or function, genetic or genomic polymorphisms of uncertain significance (gene variants, single-nucleotide polymorphisms (SNPs), and copy number variations (CNVs)), and epigenetic or epigenomic changes that influence cardiac gene functions scattered across the human genome. Recent genetic and genomic studies in both systolic and diastolic ventricular dysfunction, the hallmark of CHF, have revealed a number of mutations in genes belonging to specific cardiac protein families. For example, around 200 mutations are now known to exist in around 15 genes coding for several different types of sarcomere proteins (Liew and Dzau 2004). The sarcomere protein family, alone, accounts for the bulk of inherited cardiomyopathies including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), and left ventricular (LV) non-compaction (LVNC). In addition, there are several other potentially relevant factors involving different genes and genome-level elements. This article presents a systematic account on the available factual information and interpretations based on genetic and genomic studies in CHF (Liew and Dzau 2004). Genomic and molecular approaches have opened the way for a renewed debate for taxonomy of CHF (Ashrafian and Watkins 2007). The review draws attention to the potential diagnostic and therapeutic implications of genomic and transcriptional profiling in HF and translational genomics research that is likely to permit greater personalization of prevention and treatment strategies to address