All in the Family

"But nobody in my family has it!"

That's a common reaction patients have when told their condition is hereditary.

Saying a disease is genetic gives the patient more than just a point of information. Heredity is one of the "Big Seven," the ways people explain illness to themselves and make its appearance feel more plausible and less like a bolt from the blue: heredity, diet, environment ("the air," "the water"), allergy, infection, cancer, and aging (which explains almost anything—"When you get old, everything happens"). Calling something hereditary helps it make sense, which is useful.

What people mean by hereditary (they call it "taking after") is not the same as what we mean by genetics, although the two concepts overlap somewhat. Patients think of genetics in a global sense: If you look like someone, have the same skin type, or otherwise resemble a forebear somehow, then you're considered likely to get what they had and unlikely to get what they didn't. People are always saying things like, "I inherited my Dad's fair skin, but my sister is dark like my mother." Genetics is a bit more complex than that, of course. Besides, the alleged resemblance is supposed to explain not just being prone to skin cancer—which sounds semireasonable—but being vulnerable to lots of other diseases that have nothing to do with UV tolerance.

People also tend to think that if someone they take after had a problem to a certain extent, then they too will suffer the same way. Psoriasis does indeed have a genetic component, but onset, duration, and severity hardly follow set familial patterns.

To further complicate matters, family mythology about what so-and-so had and how bad it was may be imprecise, to say the least. Think of statements like, "My aunt had a dozen melanomas."

In addition, people assign genetics to specific things in a way we physicians never would. Many insist that their mother/sister/aunt had "the same mole" as the one we're examining or planning to biopsy. What does the same mole mean? That it occupied the same exact anatomical place? How would they know? And what difference would it make? Yet, to the patient this designation makes good sense, implying a commonality of medical fate, for good or ill, with their similarly moled relative.

So when a 40-year-old shows up with atopic dermatitis, she's going to consider it mighty unlikely that it "just came" for no reason. (She "didn't change anything," "did not eat anything different," and so forth.) Explaining that eczema is hereditary makes its arrival more reasonable to her, without the need to blame something she did or ate.

That is, if you can convince her when she claims "nobody in the family has it!" There are several reasons patients may not know any relatives with the condition:

▸ Actually, nobody does have it. Not every hereditary condition affects every family member.

▸ They would have had it if they'd lived long enough. Seborrheic keratoses, for instance.

▸ They do have it but never told you. Imagine a Thanksgiving dinner: "So how's it going, Uncle Ebenezer?" "Pretty tolerable, Clem. But those pesky skin tags in my groin've been acting up again. Got 'em from Ma."

▸ They do have it, but nobody told them. How many patients with atopic dermatitis go through life thinking or being told that they have "dry skin" or "allergies"?

Specifying genetics can have negative effects, too. Even modern folks may not be free of the guilt associated with "passing something on." Rationally, no one should feel guilty for having a gene someone gave him or her. But guilt is not rational.

Perhaps some day the Human Genome Project will provide us with a more precise and detailed understanding of what gets passed on and how. Even then, however, it will still be true that you can pick your friends …

You know the rest.

"But nobody in my family has it!"

That's a common reaction patients have when told their condition is hereditary.

Saying a disease is genetic gives the patient more than just a point of information. Heredity is one of the "Big Seven," the ways people explain illness to themselves and make its appearance feel more plausible and less like a bolt from the blue: heredity, diet, environment ("the air," "the water"), allergy, infection, cancer, and aging (which explains almost anything—"When you get old, everything happens"). Calling something hereditary helps it make sense, which is useful.

What people mean by hereditary (they call it "taking after") is not the same as what we mean by genetics, although the two concepts overlap somewhat. Patients think of genetics in a global sense: If you look like someone, have the same skin type, or otherwise resemble a forebear somehow, then you're considered likely to get what they had and unlikely to get what they didn't. People are always saying things like, "I inherited my Dad's fair skin, but my sister is dark like my mother." Genetics is a bit more complex than that, of course. Besides, the alleged resemblance is supposed to explain not just being prone to skin cancer—which sounds semireasonable—but being vulnerable to lots of other diseases that have nothing to do with UV tolerance.

People also tend to think that if someone they take after had a problem to a certain extent, then they too will suffer the same way. Psoriasis does indeed have a genetic component, but onset, duration, and severity hardly follow set familial patterns.

To further complicate matters, family mythology about what so-and-so had and how bad it was may be imprecise, to say the least. Think of statements like, "My aunt had a dozen melanomas."

In addition, people assign genetics to specific things in a way we physicians never would. Many insist that their mother/sister/aunt had "the same mole" as the one we're examining or planning to biopsy. What does the same mole mean? That it occupied the same exact anatomical place? How would they know? And what difference would it make? Yet, to the patient this designation makes good sense, implying a commonality of medical fate, for good or ill, with their similarly moled relative.

So when a 40-year-old shows up with atopic dermatitis, she's going to consider it mighty unlikely that it "just came" for no reason. (She "didn't change anything," "did not eat anything different," and so forth.) Explaining that eczema is hereditary makes its arrival more reasonable to her, without the need to blame something she did or ate.

That is, if you can convince her when she claims "nobody in the family has it!" There are several reasons patients may not know any relatives with the condition:

▸ Actually, nobody does have it. Not every hereditary condition affects every family member.

▸ They would have had it if they'd lived long enough. Seborrheic keratoses, for instance.

▸ They do have it but never told you. Imagine a Thanksgiving dinner: "So how's it going, Uncle Ebenezer?" "Pretty tolerable, Clem. But those pesky skin tags in my groin've been acting up again. Got 'em from Ma."

▸ They do have it, but nobody told them. How many patients with atopic dermatitis go through life thinking or being told that they have "dry skin" or "allergies"?

Specifying genetics can have negative effects, too. Even modern folks may not be free of the guilt associated with "passing something on." Rationally, no one should feel guilty for having a gene someone gave him or her. But guilt is not rational.

Perhaps some day the Human Genome Project will provide us with a more precise and detailed understanding of what gets passed on and how. Even then, however, it will still be true that you can pick your friends …

You know the rest.

"But nobody in my family has it!"

That's a common reaction patients have when told their condition is hereditary.

Saying a disease is genetic gives the patient more than just a point of information. Heredity is one of the "Big Seven," the ways people explain illness to themselves and make its appearance feel more plausible and less like a bolt from the blue: heredity, diet, environment ("the air," "the water"), allergy, infection, cancer, and aging (which explains almost anything—"When you get old, everything happens"). Calling something hereditary helps it make sense, which is useful.

What people mean by hereditary (they call it "taking after") is not the same as what we mean by genetics, although the two concepts overlap somewhat. Patients think of genetics in a global sense: If you look like someone, have the same skin type, or otherwise resemble a forebear somehow, then you're considered likely to get what they had and unlikely to get what they didn't. People are always saying things like, "I inherited my Dad's fair skin, but my sister is dark like my mother." Genetics is a bit more complex than that, of course. Besides, the alleged resemblance is supposed to explain not just being prone to skin cancer—which sounds semireasonable—but being vulnerable to lots of other diseases that have nothing to do with UV tolerance.

People also tend to think that if someone they take after had a problem to a certain extent, then they too will suffer the same way. Psoriasis does indeed have a genetic component, but onset, duration, and severity hardly follow set familial patterns.

To further complicate matters, family mythology about what so-and-so had and how bad it was may be imprecise, to say the least. Think of statements like, "My aunt had a dozen melanomas."

In addition, people assign genetics to specific things in a way we physicians never would. Many insist that their mother/sister/aunt had "the same mole" as the one we're examining or planning to biopsy. What does the same mole mean? That it occupied the same exact anatomical place? How would they know? And what difference would it make? Yet, to the patient this designation makes good sense, implying a commonality of medical fate, for good or ill, with their similarly moled relative.

So when a 40-year-old shows up with atopic dermatitis, she's going to consider it mighty unlikely that it "just came" for no reason. (She "didn't change anything," "did not eat anything different," and so forth.) Explaining that eczema is hereditary makes its arrival more reasonable to her, without the need to blame something she did or ate.

That is, if you can convince her when she claims "nobody in the family has it!" There are several reasons patients may not know any relatives with the condition:

▸ Actually, nobody does have it. Not every hereditary condition affects every family member.

▸ They would have had it if they'd lived long enough. Seborrheic keratoses, for instance.

▸ They do have it but never told you. Imagine a Thanksgiving dinner: "So how's it going, Uncle Ebenezer?" "Pretty tolerable, Clem. But those pesky skin tags in my groin've been acting up again. Got 'em from Ma."

▸ They do have it, but nobody told them. How many patients with atopic dermatitis go through life thinking or being told that they have "dry skin" or "allergies"?

Specifying genetics can have negative effects, too. Even modern folks may not be free of the guilt associated with "passing something on." Rationally, no one should feel guilty for having a gene someone gave him or her. But guilt is not rational.

Perhaps some day the Human Genome Project will provide us with a more precise and detailed understanding of what gets passed on and how. Even then, however, it will still be true that you can pick your friends …

You know the rest.