Introduction
Angelman syndrome (AS) is a rare genetic neurodevelopmental disorder
characterized by severe developmental delay, epilepsy, ataxic gait, and
frequent laughter or smiling. The syndrome results from a lack of
function of the imprinted ubiquitin protein ligase E3A (UBE3A) gene on
chromosome 15q11.2–q13 [1], [2]. Prevalence of AS is
approximately 1 per 20,000 births [3]. Four different molecular
defects may lead to the AS phenotype. Of these, recurrent de novointerstitial deletion of chromosomal region 15q11–q13 represents the
most common genetic mechanism, found in about 75% of individuals with
the condition [2]. Uniparental disomy (UPD), imprinting defects
(IC), and UBE3A gene mutations are additional genetic causes [2].
The severity of AS has been reported to vary among these genotypes, with
the most common also being the most severe. Most individuals with AS are
able to walk; no previously described cases have been severe enough to
bedridden [4], [5]. Although the clinical course of AS has been
reported for both children and adults, we found no examples in the
literature where laryngotracheal separation was required. Even among the
most profound forms of AS, reports of gastrostomy are few
[5]–[7]. Here we report a bedridden case who suffered frequent
episodes of aspiration pneumonia necessitating ventilator management,
and who ultimately required laryngotracheal separation (LTS).