Population genetics and disease susceptibility: characterization of central European haplogroups by mtDNA gene mutations, correlation with D loop variants and association with disease.

Mitochondrial (mt)DNA haplogroups in a German control group (n = 67) were characterized by screening mitochondrial coding regions encompassing most of the ND, tRNA and cyt b genes. We used a PCR-SSCP screening approach followed by direct sequencing of polymorphic mtDNA fragments. Five major mtDNA lineages, diverging in at least nine different haplogroups, could be defined by characteristic polymorphic sites in mitochondrial genes.

Diabetes mellitus is one of the heterogeneous phenotypic features of a mitochondrial DNA point mutation within the tRNALeu(UUR) gene.

A heteroplasmic point mutation (transition A-to-G at nucleotide position 3,243 in the mitochondrial tRNALeu(UUR) gene) is found in a family suffering from a syndrome with diabetes, deafness and cardiomyopathy as the predominant clinical features.

No genetic differences between affected and unaffected members of a German family with Leber's hereditary optic neuropathy (LHON) with respect to ten mtDNA point mutations associated with LHON.

In order to investigate possible synergistic influences of different mtDNA mutations on penetrance and severity of Leber's hereditary optic neuropathy (LHON), a large German LHON pedigree is characterized with respect to 10 different mutations associated with LHON. All members of the family carry three different mtDNA mutations (at nucleotide 4,216, 11,778 and 13,708) in a homoplasmic form, regardless of whether or not they are clinically affected. Testing for another 7 mutations reveals negative results in all family members.

Human nesidioblastosis tissue as an immunogen for generation of islet cell specific monoclonal antibodies.

Nesidioblastosis pancreas was used as an immunogen in BALB/c-mice to generate monoclonal antibodies against structures of human islet cells. Seven clones were selected by screening 311 growing hybridomas for reactivity with the rat insulinoma cell line, RIN m5F, and with cryostat sections from human pancreas. None of the selected clones reacted with pancreatic hormones or endocrine-specific peptides.