July 2026 Research Update

Severe, hard-to-control hunger was reported much more often when adults were interviewed than when they filled out a short questionnaire, meaning written questionnaires may understate how serious hyperphagia can be in Bardet-Biedl syndrome. [1]

In this UK study, only 3 of 51 adults were labeled as having severe hyperphagia by questionnaire, but 10 of 15 were labeled severe when researchers used semi-structured interviews. [1]

Most people who did an interview shifted into a higher severity category compared with their questionnaire results, including many with obesity. This matters because the way hyperphagia is measured can change how well day-to-day difficulties are recognized in research studies and care discussions. [1]

For patients and families, this study supports a simple point: how questions are asked can change what gets captured about hunger, eating behaviors, and how disruptive they are. Right now, this mainly adds understanding about measurement rather than changing treatment, but it may matter for future studies and services that rely on questionnaires to describe hyperphagia severity. [1]

What remains uncertain is how to best measure hyperphagia in a consistent way across clinics and studies, since this work did not use a Bardet-Biedl-specific validated tool and only a subset of participants completed interviews. Still, it gives a clear early signal that interviews can reveal more severe experiences than check-box style tools. [1]

This month brought two case reports showing how different genetic changes can lead to Bardet-Biedl syndrome and how eye testing can document retinal degeneration in detail. These reports do not tell how common these findings are, but they expand the set of known gene changes and inheritance patterns seen in Bardet-Biedl syndrome. [2] [3]

One report described an 18-year-old woman with Bardet-Biedl syndrome where testing found a new BBS5 variant, and the person had two copies because of paternal uniparental disomy (both copies of a chromosome segment coming from the father). The authors also used computer-based protein predictions to support the idea that this change could disrupt BBS5 function. [2]

A second report described a 9-year-old boy with BBS7 in whom genetic testing confirmed a homozygous BBS7 deletion variant, alongside detailed eye imaging and an electroretinography test showing a rod-cone dystrophy pattern (retinal degeneration affecting night and day vision). The report also noted no kidney abnormalities at the time described. [3]

For families, these reports mainly matter for understanding diagnosis and genetic explanations, not for proving how a treatment works. They show that detailed eye testing and modern genetic testing can sometimes identify a specific gene change and, in rare situations, an unusual inheritance pattern like paternal uniparental disomy. [2] [3]

What remains uncertain is how often these exact genetic changes, or this inheritance pattern, occur in other people with Bardet-Biedl syndrome, since each report describes only one patient. Even so, the cases add to the growing library of confirmed gene changes and help make future genetic results easier to interpret when similar findings appear. [2] [3]