MD · MBA
Physician specializing in genetic analysis and personalized preventive medicine, and author of Outsmart Your Genes.
Brandon Colby is a physician-expert in the fields of genetic analysis and Personalized Preventive Medicine. He holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University's Graduate School of Business, and a degree in Genetics from the University of Michigan.
Dr. Colby is the author of the book Outsmart Your Genes and has developed numerous technologies that improve the analysis, interpretation, and actionability of genome sequencing data. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (ACMG), an Associate of the American College of Preventive Medicine (ACPM), and a member of the National Society of Genetic Counselors (NSGC).
Articles by Brandon Colby, MD are reviewed for accuracy by Sequencing's medical and scientific team. This page is for informational purposes and does not constitute medical advice.
Symptoms start before age 50 in this recessive form, where PINK1 and DJ1 act together; exome sequencing found pathogenic variants in 6.25% of 80 patients studied.
Decreased-function CYP2C9 alleles predicted vestibular-cerebellar adverse reactions in one study of epilepsy patients, and plasma levels varied by age and gender.
Glycolysis depends on phosphoglycerate kinase; a single amino acid substitution leaves the PGK II enzyme less efficient and can bring hemolysis and muscle weakness.
Growth impairment, delayed puberty and central hypothyroidism follow when the pituitary underproduces hormones; PROP1, POU1F1, LHX3 and GH1 are among the genes involved.
Damage to the brain's white matter brings developmental delay, muscle weakness and speech difficulty, with POLR3A and POLR3B mutations as the usual cause.
Disrupted replication of mitochondrial DNA produces neurological, liver and muscle symptoms in POLG-related conditions such as Alpers-Huttenlocher syndrome and SANDO.
Delayed physical and cognitive development can trace to PCH1C, CACNB4 variants, MELAS or Rett syndrome, found through targeted gene panels or whole exome sequencing.
Connective tissue disease, congenital heart disease, HIV infection and portal hypertension can all accompany PAH, where genetic results inform cause and family risk.