Causes children to age rapidly and die as early as 12, usually from heart failure or strokes. Babies appear normal in infancy but have profound growth failure during the 1st year. 90% of children with progeria have a mutation on the gene that encodes the protein lamina a. Splicing occurs abnormally, we get truncated lamin A protein. Dominant inheritance, but not genetic, so each child may be a sporadic mutation. The truncated protein lamin A causes nuclear morphological abnormalities, disorganization of heterochromatin, and defective repair of DNA damage and increased genomic instability. Characteristics � short stature, low weight, loss of subcutaneous fat, head large for face, prominent scalp veins, alopecia, delayed and abnormal dentition, stiff joints, no sexual maturation. These children DO NOT experience dementias.