Case Report Discusses Movement, Language Development in Infant with PWS

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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sleep apnea, infants, children


Infants with Prader-Willi syndrome can show abnormalities in motor and verbal development within the first six months of life, a case report highlights. Better understanding and recognition of these early developmental manifestations may aid in earlier diagnosis and care during the first weeks of life.

The case was described in a study, “Early motor and pre-linguistic verbal development in Prader-Willi syndrome – A case report,” published in the journal Research in Developmental Disabilities.

Early childhood symptoms associated with Prader-Willi syndrome are fairly well-documented and include overeating (and subsequent obesity), delays in brain development, and insufficient production of growth hormones. Other manifestations associated with language, such as making unusual sounds, weak crying, and saying first words later than normal have also been reported.

However, there is still little information available on how infants with Prader-Willi syndrome develop in the first few months after they are born.

Austrian researchers reported a male infant who was referred to the hospital shortly after birth. The boy had muscle weakness and was having difficulty feeding.

He cried every once in a while in a low voice, and persistently showed insufficient feeding interest, which required intervention by placing a nasogastric tube for assisted feeding. These manifestations continued to worsen over time which, along with other physical features such as small forehead, narrow face, and undescended testicles, led to a suspicion that he might have Prader-Willi syndrome.

The diagnosis was confirmed by genetic testing when he was 24 days old, and researchers continued to monitor him closely to assess his motor and verbal development.

The infant’s muscle weakness persisted for some time. When he became more mobile, his movements were “peculiarly monotonous,” researchers noted. This kind of movement has been described in other developmental syndromes including Rett syndrome and Down syndrome, which is suggestive of impaired activity of some brain areas.

Researchers also reported that the boy had not started making “fidgety” movements at the age of 11 weeks, while commonly such movements typically start at 4 and 8 weeks and last until around 20 weeks. The boy started making fidgety movements when he was around 17 weeks and they lasted until 27 weeks, which represents a significant developmental delay.

By the age of 6 months, he was recorded making age-appropriate noises for a child between 3 and 8 months. Additionally, the team described his noises as being “partly monotonous and with a peculiar harmonic structure.” However, he still was unable to produce any of the more complicated sounds that are expected to start between 5-10 months. It’s not totally clear whether this is indicative of a true delay in verbal development, but the researchers think it likely is.

These findings highlight some of the changes observed in the early life of a child with Prader-Willi syndrome, and more studies are warranted to further validate them in a large population of patients affected by this rare disease.

“Our findings might shed some light upon early [disease-associated mechanisms] of Prader-Willi syndrome and show once more that the “how” outweighs the “if,” since the behavioral monotony was obvious before its lack of age-adequacy,” researchers concluded.