Hair loss in a 6-month-old child. Monilethrix

Monilethrix

“…[12] Monilethrix shows considerable variation in age of onset, severity and course. [13] Hair loss or broken hair is accompanied by follicular keratoses most commonly on the nape and occiput. In some cases, the eyebrows and eye lashes, pubic and axillary hair and general body hair may be affected.…”

Monilethrix in three generations

“…Inheritance is usually autosomal dominant although a recessive mode has also been reported. The affected persons tend to have short, sparse, dry, fragile beaded hair which rarely attains lengths of >2 cm, although it has been reported to grow up to 7 cm 2. We report here a rare case of this hair shaft disorder occurring in three consecutive generations.…”

“…Monilethrix, a rare hair shaft disorder, was first described by Smith in 1879 as a rare nodose condition of the hair and the term “monilethrix” was later coined by Radcliff Crocker 12. Inheritance is usually autosomal dominant although a recessive mode has also been reported.…”

“…The hair on the nape of the neck and occipital region are the most commonly affected parts but hair over the entire scalp and in other body sites such as eyelashes, eyebrows, axillary and pubic hair can also be involved 6. Inheritance is usually autosomal dominant with a high penetrance and variable expressivity; however, autosomal recessive and sporadic cases have also been reported 2. The disease develops because of mutations in genes (chromosome 12q13) that code Khb1, Khb3 and Khb6, the basic hair keratins in humans.…”

Medical Pearl: An easy way to diagnose severe neonatal monilethrix

“…Furthermore, no correlation has been found between the severity of the phenotype and the carried mutation. 6 The distortion of the hair shaft starts from the hair follicle and is demonstrable along the mature hair shaft. 7 Our observations show that although the distal end of the hair may show no beading, its proximal part will carry the typical anomaly (Fig 2).…”