Short anagen syndrome

Short anagen hair syndrome: association with mono- and biallelic variants in WNT10A and a genetic overlap with male pattern hair loss

BACKGROUND

Short anagen hair (SAH) is a rare paediatric hair disorder characterized by a short anagen phase, an inability to grow long scalp hair and a negative psychological impact. The genetic basis of SAH is currently unknown.

OBJECTIVES

To perform molecular genetic investigations in 48 individuals with a clinical phenotype suggestive of SAH to identify, if any, the genetic basis of this condition.

METHODS

Exome sequencing was performed in 27 patients diagnosed with SAH or with a complaint of short, nongrowing hair. The cohort was screened for variants with a minor allele frequency (MAF) < 5% in the general population and a Combined Annotation Dependent Depletion (CADD) score > 15, to identify genes whose variants were enriched in this cohort. Sanger sequencing was used for variant validation and screening of 21 additional individuals with the same clinical diagnosis and their relatives. Genetic association testing of SAH-related variants for male pattern hair loss (MPHL) was performed using UK Biobank data.

RESULTS

Analyses revealed that 20 individuals (42%) carried mono- or biallelic pathogenic variants in WNT10A. Rare WNT10A variants are associated with a phenotypic spectrum ranging from no clinical signs to severe ectodermal dysplasia. A significant association was found between WNT10A and SAH, and this was mostly observed in individuals with light-coloured hair and regression of the frontoparietal hairline. Notably, the most frequent variant in the cohort [c.682T>A;p.(Phe228Ile)] was in linkage disequilibrium with four common WNT10A variants, all of which have a known association with MPHL. Using UK Biobank data, our analyses showed that c.682T>A;p.(Phe228Ile) and one other variant identified in the SAH cohort are also associated with MPHL, and partially explain the known associations between WNT10A and MPHL.

CONCLUSIONS

Our results suggest that WNT10A is associated with SAH and that SAH has a genetic overlap with the common phenotype MPHL. The presumed shared biologic effect of WNT10A variants in SAH and MPHL is a shortening of the anagen phase. Other factors, such as modifier genes and sex, may also play a role in the clinical manifestation of hair phenotypes associated with the WNT10A locus.

Progressive Hair Loss With Short Hair in a Child

A school-aged girl presented to the dermatology clinic with a 6-year history of hair loss and short hair, and light microscopy of scalp hair shafts revealed no structural abnormalities, such as cuticular damage, twisting, bending, or miniaturization. What is your diagnosis?

Short anagen syndrome: A case series and algorithm for diagnosis

BACKGROUND

The short anagen syndrome (SAS) is a rare idiopathic pediatric disorder characterized by the short duration of the anagen phase. SAS mainly affects Caucasian children. Parents complain of their child's inability to grow long hair. Topical minoxidil may be an effective treatment for SAS; however, a slow spontaneous improvement is typical.

OBJECTIVE

Our aim was to collect data on out cases of SAS and create an algorithm to facilitate diagnosis of SAS.

METHODS

A retrospective review of 25 patients with SAS was performed within the Dermatology Department of the University of Bologna. We collected data regarding symptoms, pull test, hair card test, trichoscopy, trichogram, treatments, including biotin and minoxidil, and clinical outcome.

RESULTS

Characteristic findings included parental reporting that the hair had not required a haircut, hair card test showing hairs with conical-shaped tips, and hair shafts of different diameters, with more 10%-20% of hair shafts less than 60 μm thick on trichoscopy. Trichogram revealed an increased percentage of telogen hair with normal hair shafts and tapering ends. The mean anagen-to-telogen ratio was 66:34 (normal ratio 90:10).

CONCLUSION

We developed an algorithm to facilitate the diagnosis of this rare hair disease using clinical examination and invasive and non-invasive testing to differentiate SAS from other forms of pediatric alopecia. In conclusion, the collected data of the therapy showed that biotin alone or in combination with topical minoxidil is an effective treatment for SAS.

Short anagen syndrome: Case series and literature review

BACKGROUND/OBJECTIVES

Short anagen syndrome is a hair cycle disorder usually diagnosed in early childhood and characterized by short hair length due to short duration of the anagen phase. The objective was to review the presentation and demographic characteristics of short anagen syndrome and compare them with the most common differential diagnosis, loose anagen syndrome.

METHODS

A retrospective review of eight children with short anagen syndrome was performed at the University of Miami Outpatient Dermatology Clinic.

RESULTS

The diagnosis of short anagen syndrome was confirmed according to clinical findings and characteristic short telogen hairs with pointed tips on the hair pull test.

CONCLUSION

This is the largest reported clinical series of short anagen syndrome thus far in the literature.

Clinical, Microscopic and Ultrastructural Findings in a Case of Short Anagen Syndrome

Short anagen syndrome is an uncommon and recently described disease characterized by many telogen hairs and short maximum hair length. We report here the case of a 3-year-old girl whose short, sparse, fine hair since birth was consistent with short anagen syndrome. X-ray microanalysis demonstrated normal composition of the main bioelements of her hairs.

Primary scalp alopecia: new histopathological tools, new concepts and a practical guide to diagnosis

The diagnosis of primary scalp alopecia remains one of the most challenging fields in dermatopathology. In this review, we would like to connect the established classification of primary alopecia into scarring (cicatricial) and non-scarring (non-cicatricial) with current concepts. We introduce a simplified pathway for the diagnosis of the most common causes of alopecia, including a discussion of tissue processing techniques and use of immunohistochemistry.

A case of loose anagen syndrome in an African American girl

We present the case of 7-year-old African American girl with loose anagen syndrome. Although this is a common cause of hair loss in Caucasian children, and there have been reports of cases occurring in dark-skinned children of North African and Middle Eastern descent, to our knowledge there have been no cases reported in black children of sub-Saharan African ancestry. We present this case to broaden the differential diagnosis of hair loss in African Americans.

FGF5 is a crucial regulator of hair length in humans

Mechanisms that regulate the growth of eyelashes have remained obscure. We ascertained two families from Pakistan who presented with familial trichomegaly, or extreme eyelash growth. Using a combination of whole exome sequencing and homozygosity mapping, we identified distinct pathogenic mutations within fibroblast growth factor 5 (FGF5) that underlie the disorder. Subsequent sequencing of this gene in several additional trichomegaly families identified an additional mutation in FGF5. We further demonstrated that hair fibers from forearms of these patients were significantly longer than hairs from control individuals, with an increased proportion in the growth phase, anagen. Using hair follicle organ cultures, we show that FGF5 induces regression of the human hair follicle. We have identified FGF5 as a crucial regulator of hair growth in humans for the first time, to our knowledge, and uncovered a therapeutic target to selectively regulate eyelash growth.

Short anagen hair syndrome

Short anagen syndrome (SAS) is a condition in which hair does not grow long. It usually perceived by parents in children around 2-4 years of age. It is a benign disease of the hair cycle. The condition is relevant from the standpoint of differential diagnosis with loose anagen syndrome. We report a case of SAS in a Hispanic 3-year-old girl.

Short Anagen Syndrome in an Indian Woman with its Impact on Quality-of-Life

Short anagen syndrome (SAS) is a recently described entity characterized by idiopathic shortening of anagen phase. The condition is poorly described in Indian population. We describe the 1^st Indian case with clinico-pathological features of a 30-year-old woman diagnosed with SAS. Case was diagnosed on the basis of clinical examination, trichogram, microscopic examination of the hair shaft, histopathologic examination of scalp, and measurement of hair growth rate.

Self-organizing and stochastic behaviors during the regeneration of hair stem cells

Stem cells cycle through active and quiescent states. Large populations of stem cells in an organ may cycle randomly or in a coordinated manner. Although stem cell cycling within single hair follicles has been studied, less is known about regenerative behavior in a hair follicle population. By combining predictive mathematical modeling with in vivo studies in mice and rabbits, we show that a follicle progresses through cycling stages by continuous integration of inputs from intrinsic follicular and extrinsic environmental signals based on universal patterning principles. Signaling from the WNT/bone morphogenetic protein activator/inhibitor pair is coopted to mediate interactions among follicles in the population. This regenerative strategy is robust and versatile because relative activator/inhibitor strengths can be modulated easily, adapting the organism to different physiological and evolutionary needs.

Short anagen syndrome

Short anagen syndrome (SAS) is a recently described disease, but is rarely reported in the literature probably because of its under-recognized status. It is characterized by the inability to grow long hair because of an idiopathic short anagen phase. The condition is not associated with hair shaft fragility or hair unruliness. The patients complain of abnormally short scalp hair and report that they never had a haircut. The condition is benign and most of the reported cases had no associated systemic diseases or skin disorders. Hair length tends to improve spontaneously after puberty. The main differential diagnoses include loose anagen hair syndrome (LAS).

Short anagen syndrome in an African American woman

Short anagen syndrome is an uncommon condition characterized by the inability to grow long hair and an increase in the number of hairs in telogen. The incidence of short anagen syndrome is poorly documented in the medical literature. In all reports, patients are Caucasian and usually have fine blond hair. We report a case of a 38-year-old African American woman with short anagen syndrome.