Decoding Non-Obstructive Azoospermia: Genetic Insights and Testing
No sperm reaches the ejaculate because production is impaired; DMC1 and MSH4 variants have been reported, and results inform ART choices and inheritance risk.
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 Obesity: A Comprehensive Guide to Understanding, Diagnosing, and Genetic Testing
Rare single-gene changes can produce severe obesity that starts early in childhood. Targeted sequencing in a pediatric weight program and a SPINK1 case are described.
Decoding Early-Onset Obesity: A Deeper Look into Genetic Testing and Diagnosis
Obesity that starts in childhood or adolescence is often linked to mutations in genes that regulate appetite and metabolism, which genetic testing can identify.
Decoding the Genetic Puzzle: Understanding, Diagnosing, and Using Genetic Testing for Severe Obesity and Type II Diabetes
Insulin signaling differs between obese and non-obese people with diabetes, and reported subgroups carry distinct genetic and lipidomic profiles. Test uses follow.
PGBM1 with Immunodeficiency: RBCK1 Gene and Diagnosis
Polyglucosan bodies collect in muscle, heart and liver when the RBCK1 gene is mutated, bringing progressive proximal weakness, cardiomyopathy and immunodeficiency.
How PGBM1 Is Diagnosed: Muscle Biopsy and RBCK1 Testing
Muscle weakness and cardiomyopathy follow a build-up of polyglucosan bodies caused by RBCK1 mutations. Prenatal and preimplantation testing are options for carriers.
Pseudo-Fractures (Looser's Zones): Causes and Imaging
Radiolucent bands on X-ray can be mistaken for true breaks; they are tied to osteomalacia and rickets, and imaging plus gene findings point to the bone weakness.
Cracking the Code: Understanding and Diagnosing Pustular Psoriasis through Genetic Testing
Generalized pustular psoriasis and pustular psoriasis of pregnancy differ in course and therapy, and IL36RN mutations help tell the two subtypes apart.