Édouard Séguin described it as separate from cretinism in 1844. By the 20th century, Down syndrome had become the most recognizable form of mental disability. In antiquity, many infants with disabilities were either killed or abandoned. In June 2020, the earliest incidence of Down syndrome was found in genomic evidence from an infant that was buried before 3200 BC at Poulnabrone dolmen in Ireland. Researchers believe that a number of historical pieces of art portray Down syndrome, including pottery from the pre-Columbian Tumaco-La Tolita culture in present-day Colombia and Ecuador, and the 16th-century painting The Adoration of the Christ Child.In the 20th century, many individuals with Down syndrome were institutionalized, few of the associated medical problems were treated, and most people died in infancy or early adulthood. With the rise of the eugenics movement, 33 of the then 48 U.S. states and several countries began programs of forced sterilization of individuals with Down syndrome and comparable degrees of disability. Action T4 in Nazi Germany made public policy of a program of systematic involuntary euthanization.With the discovery of karyotype techniques in the 1950s it became possible to identify abnormalities of chromosomal number or shape. In 1959 Jérôme Lejeune reported the discovery that Down syndrome resulted from an extra chromosome. However, Lejeunes claim to the discovery has been disputed, and in 2014 the Scientific Council of the French Federation of Human Genetics unanimously awarded its Grand Prize to his colleague Marthe Gautier for her role in this discovery.
Pilomatricoma, is a benign skin tumor derived from the hair matrix. These neoplasms are relatively uncommon and typically occur on the scalp, face, and upper extremities. Clinically, pilomatricomas present as a subcutaneous nodule or cyst with unremarkable overlying epidermis that can range in size from 0.5 to 3.0 cm, but the largest reported case was 24 cm. Presentation
Associations
Pilomatricomas have been observed in a variety of genetic disorders including Turner syndrome, myotonic dystrophy, Rubinstein-Taybi syndrome, Trisomy 9, and Gardner syndrome. It has been reported that the prevalence of pilomatricomas in Turner syndrome is 2.6%.Hybrid cysts that are composed of epidermal inclusion cysts and pilomatricoma-like changes have been repeatedly observed in Gardner syndrome. This association has prognostic import, since cutaneous findings in children with Gardner Syndrome generally precede colonic polyposis. Histologic features
The characteristic components of a pilomatricoma include a stroma of fibrovascular connective tissue
surrounding irregularly shaped, lobulated islands containing basaloid cells (being darkly stained, round or elongated, with indistinct cell borders and minimal cytoplasm, with nuclei being round to ovoid, deeply basophilic and generally prominent nucleoli), which abruptly or gradually transitions into ghost cells (having abundant, pale, eosinophilic cytoplasm, well defined cell borders and a central clear area, but only faint traces of nuclear material), which in turn may transition into keratinaceous to amorphous necrosis.The presence of calcifications with foreign body giant cells is common within the tumors. Pathogenesis
Pilomatricoma is associated with high levels of beta-catenin caused by either a mutation in the APC gene or a stabilizing mutation in the beta-catenin gene, CTNNB1.