What is Bardet–Beidl Syndrome (BBS)?

Bardet-Biedl Syndrome (BBS) is a rare genetic condition present in roughly 1 in 100,000 people in the United Kingdom.¹ This means that individuals are born with this condition due to a change in their genes (most commonly, the genes BBS1 and BBS10).² Since BBS is a recessive condition, both parents of an affected individual are carriers of the condition: both have one faulty version of the gene. The disease occurs when the child inherits both of these faulty versions.

Although the signs of BBS can vary widely between affected individuals, one of the primary characteristics of BBS is rod-cone dystrophy. This condition affects light-receptive eye cells called rods and cones and tends to lead to vision loss.³ Obesity, polydactyly (extra fingers and/or toes), hypogonadism (undeveloped genitals), kidney abnormalities, and developmental delays are also key characteristics of BBS. In addition to these traits, people living with BBS may also display diabetes, dental and oral abnormalities, and speech disorders,⁴ the latter of which will be examined in this article.

What speech issues are seen in BBS?

To be exact, speech is defined as how we produce words and sounds. It differs from language, which encompasses the words we say and how we use them to communicate.⁵ It is estimated that around 60–84% of BBS patients display speech issues.⁶

Specifically, children with BBS may show a delay in their speech development. For example, around two-thirds of typically developing children will say their first words by one year of age and will be able to string together a few words by the age of two. However, around half of all children with BBS do not reach these developmental milestones.⁶

The way children with BBS communicate socially can also be different: almost a third of children with BBS over the age of four struggle to engage in small talk.⁷ Individuals with BBS may also talk in a high-pitched, nasal, or breathy voice.

What factors influence speech and language in BBS?

A significant factor that affects speech and language development in children is their ability to hear. Importantly, around 1 in 5 people with BBS have hearing loss.⁸ Having hearing loss means that an individual may not be able to hear certain sounds well (i.e., soft sounds, like “s”, “sh”, “f”), so children with hearing loss may struggle with saying them too. In addition, they may not be able to tell if they are speaking too loudly, too quietly, or in a high pitch.⁹

The structure and function of the mouth and face (the orofacial structure) can be different in people with BBS. For example, the muscles in the throat and vocal cords (the pharyngeal and laryngeal muscles) may not coordinate properly, which can lead to speech disorders. Also, babies with BBS may be born without some teeth (hypodontia), which can also impact their ability to speak.¹⁰

Around 75% of individuals with BBS experience a form of developmental difficulty, such as intellectual disability, and this can vary in severity between individuals.¹¹ This can impact an individual’s speech development and can limit one’s vocabulary.⁴

In addition, features of autism spectrum disorder (ASD) may be present in around 75% of people with BBS.¹² These features may manifest in the individual’s speech and language. For example, a very common trait seen in individuals with ASD is language and/or speech impairment, which can involve non-voluntarily repeating sounds or words made by others (echolalia) and an unusual vocal tone, as well as being nonverbal in some cases.¹³

How is speech and language assessed?

Initially, parents and/or carers may notice that a child has not reached certain milestones related to their speech development. Some examples of signs of speech delay include the following:

• Not using gestures (e.g., waving and pointing) by 12 months of age.
• Not being able to imitate sounds very well by 18 months of age.
• Having an unusual tone of voice (e.g., raspy, breathy, high-pitched) at 2 years of age.

Parents and/or carers are usually better at telling what their child is saying or trying to communicate. However, a typically used measure of speech ability is whether the child can be understood by people who do not know them. Specifically, it is suggested that by 4, children should be understood even by people who do not know them.¹⁴

At the first suspicion of speech-related difficulties in children with BBS, referral to a speech and language pathologist (SLP) should be sought.¹⁵ An audiologist can assess whether a child has hearing loss, which, as explained earlier, can affect speech development.

What intervention strategies are used?

It is important to note that a multidisciplinary approach is used to manage the treatment of individuals with BBS. This means that experts across a variety of different disciplines contribute to the individual’s treatment. For example, geneticists, ophthalmologists, speech-language pathologists (SLPs), and audiologists may be involved in a BBS patient’s treatment.¹⁶ An SLP will be able to assess what type of speech impairment a child is experiencing and suggest ways to encourage speech development or methods to enable the child to communicate better.

There are numerous ways that parents and carers can encourage a child’s speech development:¹⁷

• Talking as much as possible to the child
• Imitating the child’s facial expressions and sounds and getting them to imitate you is helpful and can be made into a game. For instance, games like peek-a-boo that involve imitation may be effective
• Maintaining eye contact when speaking to the child shows that you are doing so purposefully. Ensure you react when/if they speak as well
• Gesturing (pointing and waving) as much as possible may encourage the child to do so too
• Depending on the child’s age, simple picture books could be read to and with them

An SLP might recommend an augmentative and alternative communication (AAC) system for the child, depending on their abilities and needs. AAC describes methods of communication besides talking. There is a huge variety of ways in which people can communicate effectively with each other that do not involve talking. For example, gestures, facial expressions, writing, and drawing are part of the AAC system that BBS patients can employ regularly. Other types of AAC include the following:

• Eye pointing frames such as E-Tran frames: These are screens made of transparent plastic (Perspex) on which symbols and words can be attached. The user can then gaze or point at these to communicate
• Signing systems (British Sign Language or Makaton): Makaton is a type of signing system that combines symbols, signs, and speech to communicate. It is frequently used by people with learning disabilities¹⁸
• Picture exchange communication systems: These utilise cards with pictures and symbols printed on them that people can use to signify what they want to communicate. They can be compiled and organized in a book
• Electronic communication aids: These can take the form of apps or devices like tablets. Voice output communication aids (VOCAs) or speech-generating devices (SGDs) are devices that read out words and sentences according to the user clicking on letters or pictures¹⁹

An SLP will also be able to recommend that certain provisions be put in place for the child’s education.²⁰ These can involve education, health and care (EHC) plans which describe a young person’s educational needs, required support, and desired outcomes. These need to be requested via your local authority.²¹ An individual education plan (IEP) is a document outlining a child’s educational needs that helps teaching staff plan for the child at school.²²

Summary

To recap:

• BBS is a rare genetic condition that can manifest in very different ways between individuals. Not every person with BBS will display the same specific characteristic. This is why a unique approach to each child is important
• A diagnosis of BBS does not necessarily mean that a child will have speech or language issues. However, parents and carers should still be aware that these types of issues are common in children with BBS
• Early intervention when speech impairment is suspected is key, as help from SLPs can significantly improve a child’s ability to communicate. The sooner this help is sought, the sooner a child’s communication skills can potentially improve

Helpful resources

Some helpful resources for parents/carers of children with BBS are listed below.

BBS UK: This is the only registered charity for people living with BBS in the UK. Together with certain NHS trusts, they provide multidisciplinary clinics for BBS patients. They run an Advice Service for people with BBS and help them access support across a variety of areas (e.g., health, education, social care, housing, and benefits applications).

Contact: This charity offers information, advice, and support for families with disabled children. They have a helpline, support service, newsletters, and parent guides, and they also run workshops.

Speech and Language UK: This charity provides resources for parents of children facing speech development issues. They offer services (e.g., an advice line, webinars) for parents/carers to discuss concerns and learn tools to help children with speech impairments.