Bosch-Boonstra-Schaaf optic atrophy syndrome & Hypotonia

*Over 90% of those diagnosed with BBSOAS have hypotonia (low muscle tone)

*The Phenotypic Expansion of Bosch-Boonstra-Schaaf Optic Atrophy Syndrome and Further Evidence for Genotype-Phenotype Correlations (2020)

*Hypotonia means decreased muscle tone. It can be a condition on its own, called benign congenital hypotonia, or it can be indicative of another problem. It is usually detected during infancy (often referred to as “floppy baby”).

*Symptoms of Hypotonia may include:

  • Decreased muscle tone; muscles feel soft and doughy
  • Ability to extend limb beyond its normal limit (extreme flexibility)
  • Failure or delay in acquiring motor-related developmental milestones
  • Problems with feeding (inability to suck or chew for prolonged periods)
  • Shallow breathing
  • Under-active gag reflex

*Boston Children’s Hospital

*Your child’s doctor will obtain a medical history and perform a physical examination that will likely include:

  • A detailed muscle function and neurological examination
  • An assessment of motor and sensory skills
  • A balance and coordination assessment
  • A mental status assessment (child’s level of awareness and interaction)
  • Reflex and nerve function

*Treatment programs to help increase muscle strength and sensory stimulation programs are developed once the cause of your child’s hypotonia is established.Such programs usually involve physical therapy through an early intervention or school-based program among other forms of therapy.

*Boston Children’s Hospital

Download Dr. Schaaf’s letter to care providers regarding BBSOAS and the management of some of these symptoms.

Data and statistics regarding Bosch-Boonstra-Schaaf optic atrophy syndrome provided above are sourced from the paper Rech ME et al. Phenotypic expansion of Bosch-Boonstra-Schaaf optic atrophy syndrome and further evidence for genotype-phenotype correlations. Am J Med Genet A. 2020;182(6):1426-1437. doi:10.1002/ajmg.a.61580 Epub 2020 Apr 10 unless otherwise footnoted.