Growth-Hormone Deficiency In Patients Suffering From Laurence-Moon Syndrome

Background. The features of Laurence-Moon syndrome vary widely from mental retardation, hypogenitalism to retinopathy; the dominant one is progressive neurological involvement, ataxia and spastic paraplegia. Like Bardet-Biedl syndrome, its inheritance is autosomal recessive. This paper describes the endocrine investigation of a new family of Laurence-Moon syndrome subjects.Case report. The 5 patients (3 girls, 2 boys) in this family of 12 sibs, all suffered from retinopathy, mental retardation and firts metacarpal hypoplasia with proximal placement of thumb. All five had had spastic paraplegia since the age of 5-6 years, growth retardation and hypogonadism. Two had had seizures; only one was obese.Results. Four patients (2 girls, 2 boys, aged 19, 15, 18 and 19 years) had low basal plasma FSH and LH levels. They had no FSH-LH response to gonadotropin-releasing hormone; their plasma testosterone and oestradiol concentrations were very low.The growth hormone peak in response to arginine-insulin were low in these 4 patients (1.5 ng/ml; 3.8 ng/ml; 5 ng/ml; 4.8 ng/ml). One boy and one girl were given sex steroids for a few months, with good effect on their sexual characters. Their growth hormone levels remained low (2.9 ng/ml, 6.5 ng/ml). One boy was given FSH and LH analogues with good effects on sexual characters and testicle growth. He was also given growth hormone, and had a growth spurt of 5.5 cm after 9 months treatment.Conclusion. The hypogonadism of Laurence-Moon patients seems to be of central origin. It is associated with growth hormone deficiency.