Next Generation Mendelian Genetics: Muscle Hypertrophy

The NHGRI Next Generation Mendelian Genetics project uses exome resequencing to identify variants in unsolved Mendelian diseases. Samples were collected from a single, multi-generational family with the same phenotype of exaggerated muscular development (muscular hypertrophy) and strength characterized by reduced fat pad thickness under the skin. All family members deny "body building" activities, and are so far negative for known gene mutation that have been identified as associated with excessive muscle development. All family members have examples of demonstrating extraordinary strength occurring both in childhood and old age. No negative associated phenotype traits with the muscle hypertrophy phenotype have been identified.]]>
Inclusion for cases Blood relative of a single family MD clinical observation of exaggerated muscular development without exercise training Able to donate blood or saliva for DNA extraction Exclusion for cases Less than 2 years of age]]>
This basic science investigation originated when a single proband presented at a Medical Genetic Clinic with an exaggerated muscular development (muscular hypertrophy) and reported the same phenotype present in multiple family members. Children of the proband came to the clinic for enrollment into the IRB approved study that included an MD - conducted physical examination, history and blood draw for DNA extraction. Out of town family members that include the proband's siblings, mother and grandparents were consented into the study over the phone where testimonies of muscle strength were recorded. Later, these subjects sent pictures taken of their muscles in the legs, arms and back, and returned saliva kits for DNA extraction. The proband is currently scheduled for EMG and muscle biopsy exams.]]>