Rett on It

The Hereditary Principle

In episode 7 of the most recent season of Netflix’s “The Crown”, Princess Margaret goes to therapy for her depression and learns that two of her first cousins, Katherine and Nerissa Bowes-Lyon, were institutionalized for mental disabilities. I can tell you from experience that stranger things have been revealed by a good therapy sesh, but what made this realization so unusual was that as far as Margaret knew, both Katherine and Nerissa had died. As “The Crown” renewed interest in Princess Di, the subject of this month’s series, we thought it would also be appropriate to investigate what is fact and what is fiction about the Bowes-Lyon sisters and the disease that afflicted them.

Katherine and Nerissa as depicted in season 4 of “The Crown”, showing homage to the Queen on their television set. Hospital workers who cared from them over the years recalled similar instances of bowing and showing interest in the royal family. Radio Times.

Cheaper By the Cousin

Katherine and Nerissa were the daughters of John Herbert Bowes-Lyon, the brother of Queen Elizabeth’s mother. As “The Crown” correctly depicted, the girls were placed in Royal Earlswood Hospital in 1941 because of their “mental retardation”: neither learned how to talk and it has widely been reported that they only reached the cognitive level of three- or four-year-olds. Three of their cousins, Idonea, Etheldra, and Rosemary, also suffered from the same apparent genetic disease and were admitted to the hospital. According to the 1963 edition of Burke’s Peerage, a published genealogy of all the aristocracy, Katherine died in 1940 and her sister passed away in 1961. But in 1987, British tabloids discovered that this was not the case. Katherine would not pass away until 2014 at the age of 87. Nerissa had only died a year previously at the age of 66, and was buried with nothing but a plastic tag to mark her gravesite.

The plastic marker over Nerissa’s burial site. Oprah Magazine.

Immediately, rumors swirled that this was an intentional cover up by the royal family. “The Crown” depicts a conversation in which the Queen Mother tells Princess Margaret that they had to lie because the potential for genetic defects in the royal line could erode confidence in the monarchy. Katherine and Nerissa’s cousin, Lord Clinton, denied these rumors back in 1987. He claimed their mother, Fenella, had inaccurately reported the girls’ death to the Burke’s Peerage because of old age and confusion. But doubters were quick to point out that she had supplied the publication with specific dates of death, indicating more than the “vague” error Lord Clinton tried to portray. 

Despite a large network of relatives, no one attempted to correct the Peerage or even visit the sisters in the hospital. It is clear that someone knew Fenella’s report was inaccurate given that the royal household was footing the bill for the Bowes-Lyon sisters’ care, but Queen Elizabeth and her immediate family did not. Many allege that the Queen Mother learned the sisters were alive in 1982, but never contacted Burke’s Peerage or made a visit to Royal Earlswood. Despite the royal family’s repeated protest that family members visited Katherine and Nerissa, no records of any visits were found after Fenella died in 1966.  

Rare photos of the sisters. Up News Info.

Katherine would live in the hospital until it was shut down in 1996 due to poor conditions. The hospital administrator alleged that Queen Elizabeth and her mother declined to meet with him as next-of-kin in order to determine where she would live next. While we cannot speculate about the royal family’s motives, the neglect of Katherine, Nerissa, and their cousins was tragic and indicative of the darkside of royal politics. 

The X Files

The 1987 reports about the 5 cousins sparked interest about what could have been the cause of such a crippling disease. An article from that year in The Age newspaper detailed the hypothesis of Professor David Danks, who was the director of the Murdoch Institute for Birth Defects, an Australian institute established by Rupert Murdoch. Danks noted that there were no males in the Bowes-Lyon family who suffered from the mysterious disease. He therefore suspected that the defect in question was a sex-linked disease in which “male victims died in early childhood.” Danks was unwilling however to suggest a specific disorder, as there were “about 20 gene diseases” that could explain the Bowes-Lyon illness.

Because the name of the game is to learn about the brain here on ULTC, I will be less scrupulous than Danks and throw out one hypothesis: Rett syndrome. Rett syndrome is a developmental disorder causing cognitive defects, impaired brain growth, motor difficulties (including the inability to speak), and autistic-like behavior. The disease is caused by mutations in a gene called MECP2, which controls the expression of many other genes. Many of the genes controlled by the MeCP2 protein are important for brain development, explaining the downstream neurodevelopmental impairments. 

This campaign by Cure Rett highlights the range of experiences of children who suffer from Rett syndrome. Grace for Rett.

Importantly, MECP2 is located on the X chromosome. If you remember your high school biology class, biological sex is determined by the combination of sex chromosomes an individual has. Although there are aberrations in sex chromosome complement, the general rule is that females are XX and males are XY, with the Y chromosome being much smaller and containing fewer genes. Therefore, mutations in genes on the X chromosome tend to affect males more, because they don’t have the benefit of another X chromosome to pick up the slack. Rett syndrome is no exception. MECP2 mutations generally cause death in males shortly after death, so Rett syndrome is primarily a disease affecting females, which would be why there were no boys in the Bowes-Lyon family who were affected. Additionally, although most MECP2 mutations occur randomly, there are instances in which women carry one X chromosome with a mutation but do not show symptoms, what are referred to as asymptomatic carriers. It is possible that Fenella and her sister were two such carriers, explaining the odd pattern of inheritance that puzzled Danks. Research is ongoing, but there is currently no cure for Rett Syndrome or any interventions beyond physical and occupational therapy to preserve mobility.

Got So Far to Go

Rett syndrome is just one example of X-linked diseases causing mental disabilities. The true cause of Katherine, Nerissa, Idonea, Etheldra, and Rosemary’s suffering remains undetermined. But thanks to “The Crown” and other projects like the 2011 documentary “The Queen’s Hidden Cousins”, these women are no longer unknown to the world. To me, the Bowes-Lyon cousins serve as a reminder that genetic diseases are the great equalizer, affecting blue bloods and blue collars alike. Moreover, the neglect of Katherine and Nerissa shows me that we still have a lot of work to do to remove stigma surrounding mental disabilities and make sure that everyone is treated with dignity, regardless of their cognitive abilities.


Miller, J. (2020, November 15). The Crown: Queen Elizabeth’s Institutionalized Cousins. Retrieved from

O’Neill, G. (1987, April 9). Bowes-Lyons retardation gene may have killed males. The Age.

Rett Syndrome Fact Sheet. (n.d.). Retrieved from

Royal nieces cover-up denied by Lord Clinton. (1987, April 8). The Herald.

Westenfeld, A. (2020, November 21). The Queen’s Hidden Cousins Are Part of a Shameful Chapter in Royal History. Retrieved from

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