Classic and backdoor pathways of androgen biosynthesis in human sexual development

Both genes and hormones regulate human sexual development. Although ovarian hormones are not essential for female external genitalia development, male sexual development requires the action of testicular testosterone and dihydrotestosterone (DHT). DHT is the most active endogenous androgen formed by the conversion of testosterone in genital skin. This synthesis route from cholesterol to DHT is called the conventional classic pathway. Recent investigations have reported an alternative ("backdoor") route for DHT formation that bypasses fetal testicular testosterone. This alternative route plays a crucial role in human hyperandrogenic disorders like congenital adrenal hyperplasia caused by P450c21 deficiency, polycystic ovary syndrome, and P450 oxidoreductase deficiency. In addition, mutations in AKR1C2 and AKR1C4, genes encoding 3α-reductases, have been implicated in disorders of sexual development, indicating that both the classic and backdoor routes are required for normal human male sexual development. More recently, androsterone was found to be the primary androgen of the human backdoor route. Androsterone and steroidal substrates specific to the backdoor route are predominantly found in the placenta, liver, and adrenal glands rather than in the testes. These findings are essential to understanding human sexual development.

Efficacy and adverse events related to the initial dose of methimazole in children and adolescents with Graves’ disease

Purpose@#The first-line antithyroid drug for children and adolescents with Graves’ disease (GD) is methimazole (MMI). This study evaluated the relationship between the initial MMI dose and the clinical course of GD after treatment. @*Methods@#We studied the efficacy of the initial MMI dose and the relationship between the initial MMI dose and adverse events (AEs). We retrospectively enrolled 22 males and 77 females and divided those subjects into 3 groups according to the initial dose of MMI: 0.7 mg/kg/day (group C; n=28). @*Results@#The mean time to the normalization of free thyroxine (fT4) levels upon initial treatment was 5.64, 8.61, and 7.98 weeks in groups A, B, and C, respectively (P=0.116). The incidence of liver dysfunction, neutropenia, and skin rash was 12.5%, 20.5%, and 42.9% in groups A, B, and C, respectively (P=0.018). Neutropenia, as a severe AE, was absent in group A, but its prevalence was 7.7% in group B and 21.4% in group C (P=0.015). When comparing only groups B and C, the incidences of liver dysfunction and neutropenia were higher in group C (P=0.04 and P=0.021, respectively). @*Conclusion@#The mean time to the normalization of fT4 levels did not differ among the 3 groups, but the incidence of AEs was higher in the groups that received high MMI doses. High doses of MMI (>0.7 mg/kg/day) should be reconsidered as an initial treatment for children and adolescents with GD.

Efficacy and adverse events related to the initial dose of methimazole in children and adolescents with Graves’ disease

Purpose@#The first-line antithyroid drug for children and adolescents with Graves’ disease (GD) is methimazole (MMI). This study evaluated the relationship between the initial MMI dose and the clinical course of GD after treatment. @*Methods@#We studied the efficacy of the initial MMI dose and the relationship between the initial MMI dose and adverse events (AEs). We retrospectively enrolled 22 males and 77 females and divided those subjects into 3 groups according to the initial dose of MMI: 0.7 mg/kg/day (group C; n=28). @*Results@#The mean time to the normalization of free thyroxine (fT4) levels upon initial treatment was 5.64, 8.61, and 7.98 weeks in groups A, B, and C, respectively (P=0.116). The incidence of liver dysfunction, neutropenia, and skin rash was 12.5%, 20.5%, and 42.9% in groups A, B, and C, respectively (P=0.018). Neutropenia, as a severe AE, was absent in group A, but its prevalence was 7.7% in group B and 21.4% in group C (P=0.015). When comparing only groups B and C, the incidences of liver dysfunction and neutropenia were higher in group C (P=0.04 and P=0.021, respectively). @*Conclusion@#The mean time to the normalization of fT4 levels did not differ among the 3 groups, but the incidence of AEs was higher in the groups that received high MMI doses. High doses of MMI (>0.7 mg/kg/day) should be reconsidered as an initial treatment for children and adolescents with GD.

Biphenotypic acute leukemia or acute leukemia of ambiguous lineage in childhood: clinical characteristics and outcome

BACKGROUND: Acute leukemia (AL), not clearly assigned to myeloid, B-lymphoid, or T-lymphoid lineage, is classified as either biphenotypic acute leukemia (BAL) based on the European Group for Immunological Classification of Leukemias (EGIL) or acute leukemia of ambiguous lineage (ALAL) encompassing acute undifferentiated leukemia (AUL) and mixed-phenotype acute leukemia (MPAL) based on the World Health Organization (WHO) criteria. METHODS: Medical records of children newly diagnosed with BAL or ALAL, based on the EGIL or the 2008/2016 WHO criteria, respectively, admitted at Chonnam National University Hospital in 2001–2017 were retrospectively reviewed. RESULTS: Twelve (3.2%) of 377 AL patients satisfied the BAL or ALAL definitions based on the EGIL or the WHO criteria, respectively. Among 12 patients including 11 with BAL and another with undefined case based on the EGIL criteria, 7 (1.9%) had ALAL based on more stringent 2016 WHO criteria (AUL, 2; MPAL, 5). One patient had MPAL with t(9;22)(q34;q11.2), BCR-ABL+, and two had MLL gene abnormality. ALL-directed regimen was associated with better complete remission rate compared with AML-directed regimen (100.0% vs. 16.7%; P=0.015). The 5-year overall survival (OS) and event-free survival (EFS) were 51.1±15.8% and 51.9±15.7%, respectively. AUL was associated with poor OS and EFS compared with MPAL (0.0% vs. 75.0±21.7%; P=0.008). CONCLUSION: Due to the rarity of the cases, future multicenter, prospective studies incorporating large number of cases are urgently warranted to identify the clinical, biologic, and molecular markers for the prediction of prognosis and determine the best tailored therapy for each patient.

CLN6 Mutation in a Patient with Progressive Myoclonus Epilepsy / 대한소아신경학회지

Neuronal ceroid lipofuscinoses (NCLs) are inherited neurodegenerative disorders, which are caused by the accumulation of lipopigment in lysosomes. Variant forms of late infantile NCLs (vLINCLs) characterized by a later onset of seizures and visual impairment (3–8 years) than in the classic form (2–4 years) are caused by mutations of the gene encoding ceroid lipofuscinosis neuronal protein 6 (CLN6). In a girl with progressive myoclonus epilepsy, we found heterozygous variants of CLN6 (NM_017882.2; NP_060352.1): c.296A>G (p.Lys99Arg) and c.307C>T (p.Arg103Trp). They were identified with whole-exome sequencing and verified with Sanger sequencing. At 7 years and 9 months, our patient had developed multiple types of seizures, prominent myoclonus with photosensitivity, regression in motor and language skills, pyramidal and extrapyramidal signs, and brain atrophy in brain images, all of which were progressive and were compatible with vLINCLs. However, this first Korean report shows no visual impairment, which resembles the previously reported Japanese case.