A homozygous ABHD16A variant causes a complex hereditary spastic paraplegia with developmental delay, absent speech, and characteristic face

Clin Genet. 2022 Mar;101(3):359-363. doi: 10.1111/cge.14097. Epub 2021 Dec 13.

Abstract

Hereditary spastic paraplegia (HSP) is a genetically and clinically heterogeneous genetic disease characterized by progressive weakness and spasticity predominantly affecting the lower limbs. Complex HSP is a subset of HSP presenting with additional neuronal and/or non-neuronal phenotypes. Here, we identify a homozygous ABHD16A nonsense variant in two affected children in a Chilean family. Very recently, two groups reported patients with biallelic ABHD16A whose clinical presentation was similar to that of our patients. By reviewing the clinical features of these reports and our patients, ABHD16A-related HSP can be characterized by early childhood onset, developmental delay, intellectual disability, speech disturbance, extrapyramidal signs, psychiatric features, no sphincter control, skeletal involvement, thin corpus callosum, and high-intensity signals in white matter on T2-weighted brain MRI. In addition, our affected siblings showed a characteristic face, sleep disturbance, and nodular and hyperpigmented skin lesions, which have not previously been reported in this condition.

Keywords: ABHD16A; autistic behavior; autosomal recessive; characteristic face; hereditary spastic paraplegia; nonsense; skin lesion; sleep disturbance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child, Preschool
  • Homozygote
  • Humans
  • Infant, Newborn
  • Infant, Newborn, Diseases*
  • Monoacylglycerol Lipases / genetics
  • Mutation
  • Phenotype
  • Spastic Paraplegia, Hereditary* / genetics
  • Spastic Paraplegia, Hereditary* / pathology
  • Speech

Substances

  • ABHD16A protein, human
  • Monoacylglycerol Lipases