Very rare, described in 2016. Autosomal recessive transmission of a mutation of the GNB5 gene (15q21.2).  Depending on the type of mutation, a distinction is made between type 1 [MIM 617 173] and type 2 [MIM 617 182] (biallelic missense mutation), which is less severe.

A distinction is made between :

-        type 1 (or LGMLS1): psychomotor retardation, profound intellectual deficit, hypotonia, convulsions, absence or delay of language, retinal problems and bradycardia or sinus disease, which often requires the early insertion of a pacemaker

-        type 2 (or LDMLS2): language delay, developmental delay, behavioral problems (hyperactivity, attention deficit disorder), moderate intellectual retardation. Some have heart rhythm disorders similar to sinus disease.

Anesthetic implications:

preoperative ECG to detect possible sinus disease; management of a pacemaker; epilepsy; gastro-oesophageal reflux.

References :

-        Lodder EM, De Nittis P, Koopman CD, Wiszniewski W, Fischinger Moura de Souza C Lahrouchi N et al.
GNB5 mutations cause an autosomal-recessive multisystem syndrome with sinus bradycardia and cognitive disability.
Am J Human Genetics 2016 ; 99, 704-10

Updated: October 2024