The white colouration is caused by defective keratinisation
to cell arrest in the matrix.
The four-striped mouse medulla formed the centre core of the shaft and hardened by keratinisation
similar to the inner root sheath (described later).
The color becomes paler when vascularisation is reduced or epithelial keratinisation
It is suggested that RALDH2 could be involved in the maintenance of stem cells  and, given that these cells are the source of keratinocytes, abnormal levels of ATRA synthesis by RALDH2 could disrupt these keratinocyte progenitors and contribute to disorders of keratinisation
. Regulation of RALDH2 activity is essential for regulation of ATRA levels in the skin.
The various skin dermatoses seen in the elderly were papulosquamous disorders, eczematous conditions, infections and infestations, pigmentary disorders, benign tumours, miscellaneous skin conditions such as bullous disorders, disorders of keratinisation
Loci at chromosome bands 12q23.2- 24.1 and 15q25.1-26 have been reported in familial disseminated superficial actinic porokeratosis.3 Early and faulty apoptosis of keratinocytes and dysregulated keratinisation
is thought to be behind the pathogenesis.4
Addition of the monounsaturated fatty acids, oleic and palmitoleic, can induce scaly skin, abnormal keratinisation
and epidermal hyperplasia.
Disorders of keratinisation
. In Burns T, Breathnach S, Cox N, Griffiths C, eds.
Manganese: Manganese is indirectly related with the keratinisation
process of the hoof as it is required for the activation of galactotransferase and glycosyltransferase enzymes which are needed for the synthesis of chondroitin sulfate side chains of proteoglycan molecules (Keen and Zidenberg-Cherr, 1996; NRC, 2001).
DISCUSSION: CRP is rare genetically determined defect of keratinisation
characterised by persistent asymptomatic warty papular lesions of characteristic distribution with tendency to become confluent centrally & peripheral reticulated pattern.
DISCUSSION: Papillon lefevre syndrome is a disorder of keratinisation
that is inherited in a AR pattern It is characterized by progressive palmoplantar keratoderma, periodontitis [5, 10] and recurrent pyogenic infections.
DISCUSSION: Porokeratosis is an inherited disorder of keratinisation
. An autosomal dominant mode of inheritance with predilection for male sex is well established.