What does “transgenerational inheritance” mean?

Some diseases arise from unhealthy personal habits, while others result from genetic defects—leading to what is known as “skipped-generation inheritance.” But what exactly does “skipped-generation inheritance” mean?

What Is Skipped-Generation Inheritance?

Skipped-generation inheritance (also termed “atavism” in genetics) refers to a phenomenon where an individual with a hereditary disease has unaffected offspring, but subsequent generations—such as grandchildren or later descendants—exhibit the disease. This pattern reflects a specific mode of inheritance wherein certain traits reappear after several generations due to genetic recombination. Such inherited disorders do not manifest in every generation; they may only appear after two or three generations. Skipped-generation inheritance results from a combination of atavistic inheritance, epigenetic mechanisms, and polygenic inheritance.

Skipped-generation inheritance describes the reappearance of a disease-associated trait in later generations following genetic recombination. The condition does not occur in every generation; carriers of the pathogenic gene typically emerge only after several generations and then transmit the disease to their offspring. In some cases, clinical manifestations appear only after two or three generations. The most common pattern involves clinical symptoms appearing in the first and third generations, while the second generation remains asymptomatic—yet serves as carriers of the disease-causing gene.

X-linked recessive disorders are inherited in a sex-linked manner and are transmitted exclusively through females. Although female carriers themselves remain unaffected, they carry the disease-causing allele on one X chromosome and can pass it on to their male offspring, who—lacking a second X chromosome to compensate—are likely to express the disorder. We hope this explanation proves helpful.