Alopecia areata (AA) is a kind of localized scalp hair loss of sudden onset,and patients with severe AA can progress to alopecia totalis (AT) and alopecia universalis (AU).At present,AA is considered as a kind of organ-specific autoimmune disease with a genetic background,and destruction of immune privileged structures of hair follicles is an important pathogenesis of AA.Currently,therapeutic methods for AA include oral or topical glucocorticoids,intramuscular or intralesional injection of glucocorticoids,topical minoxidil tincture,etc.,but some patients still show no response to the treatments.In recent years,various clinical trials have been conducted in abroad using JAK inhibitors for the treatment of AA.Researches have revealed that about half of patients with moderate to severe AA showed almost complete recovery after the treatment with oral JAK inhibitors.Topical ruxolitinib was also reported for the treatment of AA,but patients showed different response.Although some patients suffered from recurrence after drug withdrawal or infections and other adverse reactions during the treatment,JAK inhibitors can be an effective treatment option for moderate to severe AA.

It is currently considered that alopecia areata is caused by the impairment of immune privilege in hair follicles. Stem cells have immunoregulatory functions, and can secrete a variety of cytokines to promote immune privilege in hair follicles. Stem cell therapy, especially umbilical cord- and adipose-derived stem cell therapy, has been applied to a variety of preclinical and clinical studies on alopecia, providing a new approach to refractory alopecia areata.

A case of ichthyosis follicularis,alopecia and photophobia syndrome caused by a novel mutation c.1165C＞T in the membrane-bound transcription factor protease site 2 (MBTPS2) gene was firstly reported.The proband presented with dry skin,congenital hairlessness,follicular keratotic papules,photophobia,epilepsy,and mental and motor retardation.Next-generation and Sanger sequencing analysis confirmed that the proband and his mother both had a c.1165C＞T (p.pro389Ser) mutation in exon 9 of the MBTPS2 gene.According to the clinical manifestations of the patient and genetic characteristics of the MBTPS2 gene mutation,the patient was diagnosed with ichthyosis follicularis,alopecia and photophobia syndrome.

A male patient, who was aged 3 months and 12 days, presented with well-circumscribed erythema and scales on the scrotum, perineum, buttocks and perianal region at 1 month after birth. The lesions gradually involved the perioral and axillary regions, flexor aspect of the elbow, popliteal fossa and neck. Shortness of breath, crying, dysphoria and vomiting occurred without fever and cough 3 days before hospitalization. Laboratory examinations at admission showed metabolic acidosis, hyperlactacidemia, hyperammonemia and organic aciduria. Second-generation sequencing and Sanger sequencing of the holocarboxylase synthetase gene revealed a known mutation c.1522C>T in exon 9 and a novel mutation c.1796_1814del in exon 11. According to a guideline from the American College of Medical Genetics and Genomics, this novel mutation was ranked as a pathogenic mutation. The patient was diagnosed as multiple carboxylase deficiency. His clinical symptoms were improved after oral biotin treatment, no neurological symptoms or signs were observed.