E S Lander

Human genetic linkage maps are most accurately constructed by using information from many loci simultaneously. Traditional methods for such multilocus linkage analysis are computationally prohibitive in general, even with supercomputers. The problem has acquired practical importance because of the current international collaboration aimed at constructing a complete human linkage map of DNA markers through the study of three-generation pedigrees. We describe here several alternative algorithms for constructing human linkage maps given a specified gene order. One method allows maximum-likelihood multilocus linkage maps for dozens of DNA markers in such three-generation pedigrees to be constructed in minutes.

Simple single-gene disorders in humans can be genetically mapped by using traditional methods of linkage analysis and increasingly abundant restriction fragment length polymorphisms (RFLPs). Many human diseases and traits, however, can be expected to be genetically heterogeneous (i.e., caused by any one of several genes), and traditional linkage analysis is much less effective in such circumstances. We present two methods, interval mapping and simultaneous search, designed to exploit the full power of a linkage map of the DNA markers. For the simplest situations, only 1/3 as many affected families are needed to map a heterogeneous trait by using these methods. Only 1/5-1/50 as many are needed to detect that genetic heterogeneity is present.

This review focuses on the molecular pathogenesis of Type 1 diabetes (T1D), specifically on the key autoantigens targeted by the autoimmune response and the clinical implications of their epitope specificity. T1D is characterized by the destruction of insulin-producing pancreatic β-cells. The autoimmune attack is directed against a defined set of autoantigens, primarily insulin, glutamic acid decarboxylase 65, tyrosine phosphatase-like protein, zinc transporter 8, as well as several minor autoantigens. A critical advancement in understanding the disease has been the analysis of epitope specificity, revealing that immunodominant epitopes are conformational and often localized to C-terminal protein regions, exposed during β-cell degradation. The introduction of sensitive multiplex assays for the simultaneous detection of T1D-associated autoantibodies represents a major diagnostic breakthrough. These platforms enable early diagnosis, risk stratification, and the identification of a "therapeutic window" for intervention. At this preclinical stage, antigen-specific immunotherapies aimed at restoring immune tolerance show significant promise. Ultimately, the combination of personalized diagnostic profiles, epitope mapping, and targeted therapies forms the basis for a new T1D management paradigm focused on halting the autoimmune process itself and preserving functional β-cell mass.

This review focuses on the molecular pathogenesis of Type 1 diabetes (T1D), specifically on the key autoantigens targeted by the autoimmune response and the clinical implications of their epitope specificity. T1D is characterized by the destruction of insulin-producing pancreatic β-cells. The autoimmune attack is directed against a defined set of autoantigens, primarily insulin, glutamic acid decarboxylase 65, tyrosine phosphatase-like protein, zinc transporter 8, as well as several minor autoantigens. A critical advancement in understanding the disease has been the analysis of epitope specificity, revealing that immunodominant epitopes are conformational and often localized to C-terminal protein regions, exposed during β-cell degradation. The introduction of sensitive multiplex assays for the simultaneous detection of T1D-associated autoantibodies represents a major diagnostic breakthrough. These platforms enable early diagnosis, risk stratification, and the identification of a "therapeutic window" for intervention. At this preclinical stage, antigen-specific immunotherapies aimed at restoring immune tolerance show significant promise. Ultimately, the combination of personalized diagnostic profiles, epitope mapping, and targeted therapies forms the basis for a new T1D management paradigm focused on halting the autoimmune process itself and preserving functional β-cell mass.