Introduction
SRD5A3-CDG (MIM 612379) is an extremely rare congenital disease, common
manifestations of which are global development delay, intellectual
disability, ophthalmological abnormalities (retinitis pigmentosa/retinal
dystrophy, optic nerve hypoplasia), cerebellar abnormalities, and
hypotonia (1). Only 38 cases of this disease have been reported
worldwide, presenting with a highly variable phenotype. While ataxia is
mentioned in just under half of these cases, telangiectasia is yet to be
reported (2, 3).
Ataxia and telangiectasia are clinical signs that characterize a
neurodegenerative disorder known as ataxia-telangiectasia, but can also
be seen in other genetic disorders like congenital disorders of
glycosylation (CDG) (4). Classically, ataxia-telangiectasia involves
multiple organ systems, particularly the nervous and immune systems.
From early childhood, those who inherit this autosomal recessive disease
develop ataxia: a disability in movement coordination (5). This
manifests as problems with walking, balance, and hand coordination, as
well as chorea, myoclonus, and neuropathy; a wheelchair is usually
needed by adolescence. Patients also suffer from oculomotor apraxia, a
condition where looking from one side to the other is difficult. Slurred
speech is also prominent. Telangiectasia is one of the two major
components of this condition, where enlarged blood vessels are seen in
the eyes and skin.
An important note for physicians is that alternative genetic disorders
must not be overlooked when a child presents with ataxia and
telangiectasia. In this case report, we discuss a seven-year-old boy
with a delayed diagnosis of SRD5A3-CDG (MIM 612379; homozygous variant
c.57G>A [p.Trp19Ter]), where a diagnosis of
ataxia-telangiectasia had been presumed.