Loss of function of FIGNL1, a DNA damage response gene, causes human ovarian dysgenesis

Ovarian dysgenesis (OD), an XX disorder of sex development, presents with primary amenorrhea, hypergonadotrophic hypogonadism, and infertility. In an Ashkenazi Jewish patient with OD, whole exome sequencing identified compound heterozygous frameshifts in FIGNL1, a DNA damage response (DDR) gene: c.189del and c.1519_1523del. Chromosomal breakage was significantly increased in patient cells, both spontaneously, and following mitomycin C exposure. Transfection of DYK-tagged FIGNL1 constructs in HEK293 cells showed no detectable protein in FIGNL1c.189del and truncation with reduced expression in FIGNL1c.1519_1523del (64% of wild-type [WT], P = .003). FIGNL1 forms nuclear foci increased by phleomycin treatment (20.6 ± 1.6 vs 14.8 ± 2.4, P = .02). However, mutant constructs showed reduced DYK-FIGNL1 foci formation in non-treated cells (0.8 ± 0.9 and 5.6 ± 1.5 vs 14.8 ± 2.4 in DYK-FIGNL1WT, P < .001) and no increase with phleomycin treatment. In conclusion, FIGNL1 loss of function is a newly characterized OD gene, highlighting the DDR pathway's role in ovarian development and maintenance and suggesting chromosomal breakage as an assessment tool in XX-DSD patients.

Are current cut-off values of 11-DOC in children useful for assessing suspected nonclassical congenital adrenal hyperplasia due to 11β-hydroxylase deficiency?

OBJECTIVE

A nonclassic form of 11β-hydroxylase deficiency (NC11β-OHD) has been reported to cause mild androgen excess symptoms. Currently, the gold standard for biochemical diagnosis is elevated 11-deoxycortisol (11-DOC) levels after corticotropin stimulation test (ACTHstimT). However, there are no clear 11-DOC level cutoffs. One of the accepted references for 11-DOC levels for the paediatric population was published in 1991 by Lashansky et al. AIM: To determine the correlation between 11-DOC levels measured during ACTHstimT and clinical symptoms attributed to NC11β-OHD.

DESIGN

A retrospective study including all paediatric patients who underwent ACTHstimT at Shamir Medical Center between 2007 and 2015. Clinical data were collected from the patients' medical files. Outcome measures included the number of patients with hyperandrogenism signs and predefined elevated 11-DOC cut-off levels according to Lashansky for sex and age, and according to commercial kit cut-offs.

RESULTS

Data were complete at presentation for 136 patients. Long-term clinical data were documented for 98 patients, mean follow-up duration of 3.1 years (1.37-5.09). There was no statistically significant difference in the number of cases with elevated 11-DOC according to both cut-offs and early puberty, premature adrenarche nor acne. Follow-up data demonstrated no statistically significant difference in the number of cases with elevated 11-DOC levels among patients with compromised final adult height, polycystic ovarian syndrome or hyperandrogenism.

CONCLUSIONS

Basal and corticotropin stimulated 11-DOC levels were not significantly elevated above the 1.5 times cut-offs according to paediatric-specific norms or the commercial assay in paediatric individuals with possible clinical suspicion of NC11β-OHD.

Are Current Normal Values of 11DOC Useful for Diagnosis of Non Classical Congenital Adrenal Hyperplasia Due to 11β- Hydroxylase Deficiency?

Background: A non-classic form of 11β-hydroxylase deficiency (NC 11β-OHD) has been reported to cause mild androgen excess, with a clinical presentation of precocious puberty, menstrual cycle abnormalities, or hirsutism during adolescence. Since genetic diagnosis of NC 11βOHD is yet not routinely available, the current gold standard for biochemical diagnosis is elevated 11 DOC levels after corticotropin stimulation test (ACTHstimT). However, there are no clear hormone level cutoffs. One of the accepted references for basal and stimulated levels for the pediatric population was published in 1991 by Lashansky et al¹. Aim: To determine the correlation between 11DOC levels measured during ACTHstimT, clinical symptoms attributed to NC11βOHD and androgen levels at presentation, and long-term follow-up among children and adolescents with hyperandrogenism. Methods: a retrospective study including all patients who underwent ACTHstimT between 20072015, in one center, during which 11 DOC levels were routinely measured as part of the test. Clinical data was collected from the patients’ medical files and, by telephone calls for complete long-term follow-up. 11DOC levels before and after ACTHstimT were categorized as elevated according to both pre-defined cut-offs; greater than 1.5 times the 95th percentile according to Lashansky¹ normal level for sex and age, and greater than 1.5 times the upper limit of the normal level of the commercial kit. Results: Data were complete at presentation for 136 patients, 92 females, and for long for 98 patients, 68 females, mean follow up duration of 3.1 years (1.37,5.09). There was no statistically significant difference in the number of cases with elevated 11DOC according to both cut-offs, among patients with precocious and early puberty, premature adrenarche nor acne. Higher baseline and stimulated 11 DOC levels were demonstrated in females who presented with mild hirsutism and regular menses. Long term data demonstrated no statistically significant difference in the number of cases with elevated 11DOC levels among patients with compromised final adult height, PCOS or hyperandrogenism. There was negative correlation between stimulated 11 DOC levels and basal levels of testosterone, androstenedione and DHEAS levels. Conclusions: This report demonstrates that the current interpretation of 11DOC levels, basal and ACTHstimulated in children, according to 1.5 times the highest range, of both, the Lashansky¹ acceptable norms for children, and some of the laboratory’s kit, are not clinically applicable.¹Lashansky G, Saenger P, Fishman K, Gautier T, Mayes D, Berg G and Reiter E. Normative data for adrenal steroidogenesis in a healthy pediatric population: Age- and sex-related changes after adrenocorticotropin stimulation. J. Clin. Endocrinol. Metab. 1991; 73(3): 674-686.

Bone Age Assessments by Quantitative Ultrasound (SonicBone) and Hand X-ray Based Methods are Comparable

BACKGROUND

Bone maturation is currently assessed by subjective and automated radiography.

OBJECTIVES

To evaluate the concordance and reproducibility of a quantitative ultrasound (QUS) based device versus X-ray based methods.

METHODS

The study population comprised 150 children, 76 males, 4-17 years of age. X-ray scans were evaluated according to wrist, carpal and phalanx areas for bone age. QUS was performed by the the BAUS™ device (SonicBone, Rishon Lezion, Israel), using speed-of-sound (SOS) and distance attenuation factor (ATN) in similar areas. Data from 100 subjects were used to establish the device conversion equation, and 50 measurements were assigned to assess inter-modality agreement.

RESULTS

BAUS showed high repeatability performance, 0.73% relative standard deviation for SOS and 3.5% for ATN. R2 for the conversion equation, including gender, SOS, and ATN, was 0.80 for all methods (P < 0.001). There was no significant bias in bone age assessments.

CONCLUSIONS

Bone age assessment by SonicBone is comparable to the assessment by X-ray based methods.