Oskar Kobylinski (1856-1926) and the first description of Noonan syndrome in the medical literature.

While a student of University in Dorpat (now Tartu, Estonia) Oskar Kobylinski published an article reporting on his 22-year-old patient Leisar Eischikmann, who suffered from a congenital deformity of the neck. Kobylinski described this rare anomaly and called it "flüghautige Verbreitung des Halses" (wing-like extension of the neck). It was only in 1902 when the name pterygium colli was introduced, and it has been in use ever since. This malformation is part of some congenital syndromes, most prominently, Turner syndrome and, more rarely, of Noonan syndrome. As Opitz et al. pointed out, the patient described in the 1883 article from Archiv für Anthropologie is probably the first person with Noonan syndrome to have been pictured in the medical literature. The article was signed only by "O. v. Kobylinski, student of medicine." Further archival research was needed to identify this physician and provide more details about his unusual career.

Marathon of eponyms: 14 Noonan syndrome.

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Noonan syndrome.

Noonan syndrome and related disorders: genetics and pathogenesis.

Noonan syndrome is a pleiomorphic autosomal dominant disorder with short stature, facial dysmorphia, webbed neck, and heart defects. In the past decade, progress has been made in elucidating the pathogenesis of this disorder using a positional cloning approach. Noonan syndrome is now known to be a genetically heterogeneous disorder with nearly one half of cases caused by gain-of-function mutations in PTPN11, the gene encoding the protein tyrosine phosphatase SHP-2. Similar germ line mutations cause two related genetic disorders, Noonan-like disorder with multiple giant cell lesion syndrome and LEOPARD syndrome, and somatic PTPN11 mutations can underlie certain pediatric hematopoietic malignancies, including juvenile myelomonocytic, acute lymphoblastic, and acute myelogenous leukemias. A mouse model of PTPN11-related Noonan syndrome was recently generated, providing a reagent for studying disease pathogenesis in greater depth as well as experimenting with novel therapeutic strategies.

Brief historical note: the concept of "gonadal dysgenesis".

The history of gonadal by dysgenesis cautions against overinterpretation of data: The streak gonads are neither the result of dysgenesis nor of embryonic origin but represent late fetal/neonatal degeneration; the X-chromatin-negative character of the buccal smear and the frequency of color vision defects did not indicate male sex in the Ullrich-Turner syndrome but rather an XO constitution; severity of dysgenesis did not correlate with risk of gonadal neoplasia but with genotype; the gonadal lesion in the Ullrich-Turner syndrome was not due to a pituitary defect but a primary ovarian lesion; patients with the Noonan syndrome do not have the Turner phenotype. The concept of gonadal dysgenesis, introduced to Kermauner in 1912, has outlived its usefulness. Improved methods of phenotype analysis, family studies, and endocrine and cytogenetic methods have showen it to be causally and pathogenetically heterogeneous and have contributed to a better identification and delineation of the several different genetic entities which it formerly comprised.