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.
Slow onset and symptoms resembling other neurodegenerative diseases make the adult form hard to identify. Finding HEXB mutations confirms it and guides counseling.
Beta-hexosaminidase deficiency lets harmful lipids build up in the brain, bringing muscle weakness, motor regression and seizures within the first months of life.
Symptoms appear between ages 2 and 5 as lipids accumulate in the brain. A point mutation in intron 12 of the beta-hexosaminidase beta chain gene disrupts normal splicing.
Neuraminidase deficiency from NEU1 gene mutations lets sialic acids build up in tissues, causing vision problems, muscle weakness and neurological effects.
Two copies of the altered hemoglobin gene, one from each parent, cause sickle cell disease; newborn screening and carrier testing shape early care and family planning.
Inheriting one HbS gene and one HbC gene produces the rigid red cells of sickle cell-hemoglobin C disease, with anemia and pain episodes; screening starts at birth.
Burning pain, tingling and numbness in the extremities follow faulty sodium channels, and gene testing can confirm SC-SFN when biopsy and nerve studies are unclear.
Missing or fused digits give the hands and feet a split appearance in SHFM; a complex structural variant near the SOX3 gene has been linked to the malformation.