Expanding the Phenotypic Spectrum of SLC1A4-Related Spastic Tetraplegia: A Case With Novel Multisystem Features.

Spastic tetraplegia, thin corpus callosum, and progressive microcephaly (SPATCCM) is a rare autosomal recessive neurodevelopmental disorder caused by pathogenic variants in the SLC1A4 gene. 24 cases have been reported worldwide. We describe a 30-month-old boy born to consanguineous parents, presenting with global developmental delay, seizures, progressive microcephaly, spastic tetraplegia, feeding difficulties, and recurrent infections. Genetic testing confirmed a homozygous pathogenic variant in SLC1A4 (p.Arg457Trp). Notably, our patient exhibited novel systemic phenotypic features, including grade 2 finger clubbing, recurrent infections, bilateral hernias, meatal stenosis, and dysmorphic features (high-arched palate, low-set ears, pectus carinatum). Brain MRI demonstrated a diffusely thin corpus callosum, a typical finding consistent with the classic SPATCCM phenotype. These previously unreported systemic features broaden the recognized phenotypic spectrum and underscore the need for genetic testing in suspected cases.