AIM: Benign hereditary chorea is a dominantly inherited, childhood-onset 
hyperkinetic movement disorder characterized by non-progressive chorea and 
variable degrees of thyroid and respiratory involvement. Loss-of-function 
mutations in NKX2.1, a gene vital to the normal development and function of the 
brain, lungs, and thyroid, have been identified in a number of individuals.
METHOD: Clinical data from individuals with benign hereditary chorea identified 
through paediatric neurology services were collected in a standardized format. 
The NKX2.1 gene was analysed by Sanger sequencing, multiplex ligation-dependent 
probe amplification, and microarray analysis.
RESULTS: Six of our cohort were female and four male, median age at assessment 
was 8 years 6 months (range 1 y 6 mo-18 y). We identified 10 probands with 
NKX2.1 mutations; nine of these mutations are novel (including two whole-gene 
deletions) and one has been previously reported. Of the 10 individuals, eight 
presented with muscle hypotonia and four had evidence of hypothyroidism or 
respiratory involvement. Only three out of the 10 individuals had the full triad 
of 'brain-lung-thyroid syndrome' symptoms. Additional clinical characteristics 
occurring in individual participants included growth hormone deficiency, pes 
cavus, kyphosis, duplex kidney, and obsessive-compulsive disorder.
INTERPRETATION: Our data suggest that the neurological phenotype is prominent in 
this condition and that many patients with benign hereditary chorea do not have 
the classic triad of brain-lung-thyroid syndrome. The extended phenotype may 
include obsessive-compulsive disorder and skeletal abnormalities.