RT Journal Article SR Electronic T1 Watson syndrome: is it a subtype of type 1 neurofibromatosis? JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 752 OP 756 DO 10.1136/jmg.28.11.752 VO 28 IS 11 A1 Allanson, J E A1 Upadhyaya, M A1 Watson, G H A1 Partington, M A1 MacKenzie, A A1 Lahey, D A1 MacLeod, H A1 Sarfarazi, M A1 Broadhead, W A1 Harper, P S YR 1991 UL http://jmg.bmj.com/content/28/11/752.abstract AB Over 20 years ago, Watson described three families with a condition characterised by pulmonary valvular stenosis, café au lait patches, and dull intelligence. Short stature is an additional feature of this autosomal dominant condition. A fourth family with Watson syndrome has since been reported. We have had the opportunity to review members of three of these four families. The clinical phenotype of Watson syndrome has been expanded to include relative macrocephaly and Lisch nodules in the majority of affected subjects, and neurofibromas in one-third of family members. Because the additional clinical findings enhance the similarity between Watson syndrome and neurofibromatosis 1, molecular linkage studies have been performed using probes flanking the NF1 gene on chromosome 17. Probe HHH202 showed the tightest linkage to Watson syndrome with a maximum lod score of 3.59 at phi = 0.0 (95% confidence limits of phi = 0.0-0.15). This suggests either that Watson syndrome and neurofibromatosis 1 are allelic, or that there is a series of contiguous genes for pulmonary stenosis, neurocutaneous anomalies, short stature, and mental retardation on 17q.