This page is a directory of every inherited condition and inheritance topic covered on Clinical Genetics Primer. We group the entries by cluster so related conditions, their shared biology, and the practical questions families and clinicians ask about them sit near each other.

Resources like the NIH Genetic and Rare Diseases Information Center (GARD) maintain much larger disease directories for exactly this reason: a rare or inherited condition is easier to understand once a reader can see where it sits relative to similar conditions, not in isolation. Our directory below works the same way on a smaller, curated scale.

Educational, not diagnostic. Nothing on this page or linked from it is meant to diagnose a condition in a specific person. If you recognize features described here in yourself or a family member, the next step is a conversation with a genetic counselor or your clinician, not a conclusion drawn from this directory.

Ectodermal and skin-related genetic conditions

This cluster covers conditions that affect tissues derived from the embryonic ectoderm, principally skin, hair, teeth, and sweat glands, along with how they are inherited and managed.

Neurogenetic conditions

This cluster covers inherited conditions that primarily affect brain development and the nervous system, several of which share overlapping features such as seizures or developmental delay.

  • Angelman syndrome: a neurodevelopmental condition caused by loss of function of the maternally inherited UBE3A gene, with developmental delay, movement differences, and a characteristically happy demeanor.
  • Rett syndrome: a condition, usually caused by MECP2 variants, where development appears typical at first and then regresses in early childhood.
  • Tuberous sclerosis complex: a condition that causes benign tumors to form in multiple organs, including the brain, and is often associated with seizures.
  • Fragile X syndrome: the most common inherited cause of intellectual disability, linked to an expansion in the FMR1 gene on the X chromosome.
  • Genetic epilepsies overview: how seizure disorders with an identifiable genetic cause differ from epilepsy more broadly, and what that distinction means for families.

Inheritance basics

This cluster explains the mechanics of how genetic conditions pass through families, the foundation for understanding any specific condition listed above.

  • Inheritance basics: a plain-language introduction to how genes are passed from parents to children and why that matters for risk.
  • Autosomal dominant inheritance: how a single altered copy of a gene can be enough to cause a condition, and what that means for recurrence risk.
  • Autosomal recessive inheritance: why some conditions only appear when a child inherits an altered copy of a gene from both parents.
  • X-linked inheritance: how genes located on the X chromosome produce different inheritance risks for sons and daughters.
  • De novo variants: what it means when a genetic variant appears in a child but in neither parent.
  • Genomic imprinting: why a small number of genes behave differently depending on whether they were inherited from the mother or the father.

Testing and definitions

This cluster covers how genetic testing and counseling work in practice, along with a reference glossary for terms used throughout the site.

  • Genetic testing and counseling: what genetic testing can and cannot tell a family, and what a genetic counseling appointment typically involves.
  • Glossary: plain-language definitions of the clinical and genetic terms used across this site.

If a condition you are looking for is not listed here, it is outside the current scope of this site. We add new entries deliberately, so the directory stays accurate rather than exhaustive.