RAPSN-Related Disorders: Muscle Weakness and Fatigue
When the RAPSN gene is altered, nerve signals reach muscle poorly, causing weakness and fatigue. EMG, nerve conduction studies and DNA testing point to the diagnosis.
Brandon Colby, MD
MD · MBA
Physician specializing in genetic analysis and personalized preventive medicine, and author of Outsmart Your Genes.
About Brandon
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).
Education
- BA in Genetics with Honors, University of Michigan · 2000
- MD, Mount Sinai School of Medicine · 2004
- MBA, Stanford University Graduate School of Business · 2007
Affiliations & Memberships
- Affiliate Specialist, American College of Medical Genetics and Genomics (ACMG)
- Associate, American College of Preventive Medicine (ACPM)
- Member, 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.
Articles by Brandon
Decoding RBBP8-Related Disorders: Genetic Testing for Diagnosis and Management
Mutations in the RBBP8 gene underlie Seckel, Jawad and Cohen-Gibson syndromes, rare conditions involving growth delay and intellectual disability.
Renal Hypomagnesemia, Dominant: CLDN16 and CLDN19
Low blood magnesium, high urinary calcium and kidney calcium deposits mark this disorder; blood, urine and imaging tests precede CLDN16 or CLDN19 analysis.
Unlocking the Mystery of Recessive Renal Hypomagnesemia: A Comprehensive Guide
A child is affected only when both parents pass on a mutated copy of CLDN16, CLDN19, FXYD2 or EGF, so carrier testing informs family planning and prenatal screening.
Understanding, Diagnosing, and Using Genetic Testing for Dominant Retinitis Pigmentosa
One copy of the mutated gene from a single parent is enough to cause this form. Symptoms begin in childhood, and ERG and OCT support the eye examination.
Understanding, Diagnosing, and Using Genetic Testing for Retinitis Pigmentosa
About 1 in 4,000 people worldwide have retinitis pigmentosa, linked to mutations in over 60 genes. Testing shows whether it is dominant, recessive or X-linked.
Retinitis Pigmentosa: A Comprehensive Guide to Diagnosis and Genetic Testing
When both parents pass on a mutated copy, a child develops recessive RP. A fundus exam shows bone spicule pigment, and carrier testing clarifies family risk.
Decoding RYR1-Related Disorders: Genetic Testing for a Better Understanding
A faulty ryanodine receptor brings muscle weakness, low tone and susceptibility to malignant hyperthermia. Subtypes, carrier status and anesthesia planning are covered.