A Case of 17α-hydroxylase/17,20-lyase Deficiency Diagnosed at 45 Years of Age with Hyperaldosteronism

17α-hydroxylase deficiency is a type of congenital adrenocortical hyperplasia that is typically diagnosed in childhood or adolescence. It manifests as hypertension with gonadal dysfunction as the primary symptom. We herein report 17α-hydroxylase/17,20-lyase deficiency (17OHD) diagnosed at the age of 45 years. The patient presented with hypertension, irregular menstruation, and hyperaldosteronism. The clinical manifestations of 17OHD vary based on the specific variant pattern of CYP17A1. In this case, the variant was c.157_159 TCC del p. Phe53del, which has been frequently reported in Japan. The enzymatic deficiency due to this variant is partial, leading to a delay in making a correct diagnosis.

Expression levels and DNA methylation profiles of the growth gene SHOX in cartilage tissues and chondrocytes

All attempts to identify male-specific growth genes in humans have failed. This study aimed to clarify why men are taller than women. Microarray-based transcriptome analysis of the cartilage tissues of four adults and chondrocytes of 12 children showed that the median expression levels of SHOX, a growth gene in the pseudoautosomal region (PAR), were higher in male samples than in female samples. Male-dominant SHOX expression was confirmed by quantitative RT-PCR for 36 cartilage samples. Reduced representation bisulfite sequencing of four cartilage samples revealed sex-biased DNA methylation in the SHOX-flanking regions, and pyrosequencing of 22 cartilage samples confirmed male-dominant DNA methylation at the CpG sites in the SHOX upstream region and exon 6a. DNA methylation indexes of these regions were positively correlated with SHOX expression levels. These results, together with prior findings that PAR genes often exhibit male-dominant expression, imply that the relatively low SHOX expression in female cartilage tissues reflects the partial spread of X chromosome inactivation into PAR. Altogether, this study provides the first indication that sex differences in height are ascribed, at least in part, to the sex-dependent epigenetic regulation of SHOX. Our findings deserve further validation.

Case Report: Novel compound heterozygous TPRKB variants cause Galloway-Mowat syndrome

Background

Galloway-Mowat syndrome (GAMOS) is a rare genetic disease characterized by early-onset nephrotic syndrome and microcephaly with central nervous system abnormalities. Pathogenic variants in genes encoding kinase, endopeptidase, and other proteins of small size (KEOPS) complex subunits cause GAMOS. The subunit TPRKB (TP53RK binding protein) has been reported in only two patients with GAMOS with homozygous missense variants.

Clinical report

Herein, we described a three-year-old male with GAMOS. He exhibited developmental delay, developmental regression, microcephaly, distinctive facial features, skeletal abnormalities, and epilepsy. Brain magnetic resonance imaging revealed progressive brain atrophy, delayed myelination, T2-hypointense signals in the thalamus, and multiple intracranial abnormal signals on diffusion-weighted imaging. He presented with relapsing nephrotic proteinuria exacerbated by upper respiratory tract infections and progressive renal function decline. Exome sequencing identified compound heterozygous missense and frameshift variants in TPRKB: c.224dup, p.(Ser76IlefsTer3) and c.247C>T, p.(Leu83Phe).

Conclusions

Our study supports that pathogenic TPRKB variants cause KEOPS complex-related GAMOS.

Diabetes mellitus with severe insulin resistance in a young male patient with a heterozygous pathogenic IRS1 frameshift variant

We present the case of a young male patient (height, 158.1 cm [+3.3 standard deviation (SD)]; weight, 63.7 kg [body mass index, 25.5]) with diabetes mellitus and severe insulin resistance associated with a heterozygous pathogenic insulin receptor substrate 1 (IRS1) frameshift mutation. The patient also had severe acanthosis nigricans. Notably, the patient's father was undergoing treatment with high doses of insulin for diabetes mellitus, and had been experiencing angina pectoris. Laboratory data showed a fasting plasma glucose level of 88 mg/dL, hemoglobin A1C (HbA1c) of 7.4%, fasting insulin level of 43.1 µg/mL, and a homeostasis model assessment-insulin resistance (HOMA-IR) score of 9.36, indicating hyperinsulinism. Oral glucose tolerance test revealed a diabetic pattern and insulin hypersecretion. In addition, the patient had hyperlipidemia. Genetic studies revealed a heterozygous frameshift variant of IRS1 [NM_005544.3:c.1791dupG:p.(His598Alafs*13)] in the patient and his father, which can impair the binding and activation of phosphoinositide 3 (PI-3) kinase and defectively mediate the translocation of glucose transporter type 4 (GLUT4) in adipose tissues, possibly leading to glucose intolerance. Therefore, this variant may be disease causing. After confirming IRS1 mutation, metformin was administered, and physical exercise and dietary management were initiated; metformin was well tolerated, and optimal glycemic control was maintained.

RNA sequencing and target long-read sequencing reveal an intronic transposon insertion causing aberrant splicing

More than half of cases with suspected genetic disorders remain unsolved by genetic analysis using short-read sequencing such as exome sequencing (ES) and genome sequencing (GS). RNA sequencing (RNA-seq) and long-read sequencing (LRS) are useful for interpretation of candidate variants and detection of structural variants containing repeat sequences, respectively. Recently, adaptive sampling on nanopore sequencers enables target LRS more easily. Here, we present a Japanese girl with premature chromatid separation (PCS)/mosaic variegated aneuploidy (MVA) syndrome. ES detected a known pathogenic maternal heterozygous variant (c.1402-5A>G) in intron 10 of BUB1B (NM_001211.6), a known responsive gene for PCS/MVA syndrome with autosomal recessive inheritance. Minigene splicing assay revealed that almost all transcripts from the c.1402-5G allele have mis-splicing with 4-bp insertion. GS could not detect another pathogenic variant, while RNA-seq revealed abnormal reads in intron 2. To extensively explore variants in intron 2, we performed adaptive sampling and identified a paternal 3.0 kb insertion. Consensus sequence of 16 reads spanning the insertion showed that the insertion consists of Alu and SVA elements. Realignment of RNA-seq reads to the new reference sequence containing the insertion revealed that 16 reads have 5' splice site within the insertion and 3' splice site at exon 3, demonstrating causal relationship between the insertion and aberrant splicing. In addition, immunoblotting showed severely diminished BUB1B protein level in patient derived cells. These data suggest that detection of transcriptomic abnormalities by RNA-seq can be a clue for identifying pathogenic variants, and determination of insert sequences is one of merits of LRS.

Sotos syndrome with marked overgrowth in three Japanese patients with heterozygous likely pathogenic NSD1 variants: case reports with review of literature

We report three Japanese patients with Sotos syndrome accompanied by marked overgrowth, i.e., a 2 8/12-year-old boy with a height of 105.2 cm (+4.4 SD) (patient 1), the mother of patient 1 with a height of 180.8 cm (+4.1 SD) (patient 2), and a 12 10/12-year-old girl with a height of 189.4 cm (+6.3 SD) (patient 3). In addition to the marked overgrowth (tall stature), patients 1-3 exhibited Sotos syndrome-compatible macrocephaly and characteristic features, whereas intellectual and developmental disabilities remained at a borderline level in patient 1 and were apparently absent from patients 2 and 3. Thus, whole exome sequencing was performed to confirm the diagnosis, revealing a likely pathogenic c.6356A>G:p.(Asp2119Gly) variant in NSD1 of patients 1 and 2, and a likely pathogenic c.6599dupT:p.(Ser2201Valfs*4) variant in NSD1 of patient 3 (NM_022455.5). The results, in conjunction with the previously reported data in nine patients with marked overgrowth (≥4.0 SD), imply that several patients with Sotos syndrome have extreme tall stature even in adulthood. Thus, it is recommended to examine NSD1 in patients with marked overgrowth as the salient feature.

Efficacy and safety of GH treatment in Japanese children with short stature due to SHOX deficiency: a randomized phase 3 study

We conducted a randomized phase 3 study to investigate the efficacy and safety of GH treatment in prepubertal Japanese patients with short stature due to SHOX deficiency. The patients were randomly allocated to the GH-GH group (n = 10), in which the patients were treated with GH (0.35 mg/kg/wk) subcutaneously once daily for 24 mo, or the no-treatment (NT)-GH group (n = 9), in which the patients were untreated for the first 12 mo and then administered the same dosage of GH for the next 12 mo. At month 12, the ∆height standard deviation score (SDS) for chronological age (CA) and serum IGF-1 level were significantly higher in the GH-GH group than those in the NT-GH group. In contrast, bone age (BA) and ΔBA/ΔCA were numerically higher in the GH-GH group but were not statistically significant. At month 24, these parameters were comparable between the two groups. The height velocity was significantly larger in the GH-GH group during the first year and in the NT-GH group during the second year. No serious adverse drug reactions were observed; however, one patient in the GH-GH group exhibited increased insulin resistance at month 24. These results indicated that GH is a promising treatment option for short stature in patients with SHOX deficiency.

Multiple TP53 p.R337H haplotypes and implications for tumor susceptibility

The germline TP53 p.R337H mutation is reported as the most common germline TP53 variant. It exists at a remarkably high frequency in the population of southeast Brazil as founder mutation in two distinct haplotypes with the most frequent co-segregating with the p.E134∗ variant of the XAF1 tumor suppressor and an increased cancer risk. Founder mutations demonstrate linkage disequilibrium with neighboring genetic polymorphic markers that can be used to identify the founder variant in different geographic regions and diverse populations. We report here a shared haplotype among Brazilian, Portuguese, and Spanish families and the existence of three additional distinct TP53 p.R337H alleles. Mitochondrial DNA sequencing and Y-STR profiling of Brazilian carriers of the founder TP53 p.R337H allele reveal an excess of Native American haplogroups in maternal lineages and exclusively European haplogroups in paternal lineages, consistent with communities established through male European settlers with extensive intermarriage with Indigenous women. The identification of founder and independent TP53 p.R337H alleles underlines the importance for considering the haplotype as a functional unit and the additive effects of constitutive polymorphisms and associated variants in modifier genes that can influence the cancer phenotype.

A novel GNAS-Gsα splice donor site variant in a girl with pseudohypoparathyroidism type 1A and her mother with pseudopseudohypoparathyroidism

We encountered a Chinese girl with pseudohypoparathyroidism type 1A (PHP1A) and her mother with pseudopseudohypoparathyroidism (PPHP). Sequencing analysis of GNAS-Gsα revealed a heterozygous c.212+2T>C variant (NM_000516.4) affecting the canonical splice donor site of intron 2 in the girl and her mother. RT-PCR performed on mRNA samples obtained from cycloheximide-treated and cycloheximide-untreated lymphoblastoid cell lines of this girl revealed the utilization of an alternative splice donor site at 33-34 bp from the boundary between exon 2 and intron 2 and the production of an aberrant mRNA with a retention of a 32 bp intronic sequence between exon 2 and exon 3 (p.(Gly72Lysfs*39)), which satisfied the condition for the occurrence of nonsense-mediated mRNA decay, as predicted by SpliceAI. This study revealed the molecular consequences of disruption of the canonical splice donor site and confirmed the clinical utility of SpliceAI.

TBX5 pathogenic variant in a patient with congenital heart defect and tracheal stenosis

Congenital tracheal stenosis is a rare life-threatening disorder caused by narrow O-shaped tracheal ring without smooth muscle. Its underlying genetic cause has not been elucidated. We performed whole exome sequencing in a patient with congenital tracheal stenosis and congenital heart defect, and identified a de novo pathogenic TBX5 variant (NM_181486.4:c.680T>C, p.(Ile227Thr)). The Ile227Thr-TBX5 protein was predicted to have a decreased stability by in silico protein structural analyses, and was shown to have a significantly reduced activity for the NPPA promoter by luciferase assay. The results, together with the expression of mouse Tbx5 in the lung and trachea and the development of tracheal cartilage dysplasia in the lung-specific Tbx5 null mice, imply the relevance of TBX5 pathogenic variants to congenital tracheal stenosis.

(Epi)genetic and clinical characteristics in 84 patients with pseudohypoparathyroidism type 1B

OBJECTIVE

Pseudohypoparathyroidism type 1B (PHP1B) caused by methylation defects of differentially methylated regions (DMRs) on the GNAS locus can be categorized into groups according to etiologies and methylation defect patterns of the DMRs. The aim of this study was to clarify the clinical characteristics of each group.

DESIGN

Comprehensive molecular analyses consisting of methylation, copy number, and microsatellite analyses.

METHODS

Eighty-four patients with PHP1B were included in this study. We classified them into 5 groups, namely, autosomal dominant inheritance-PHP1B (Group 1, G1), sporadic-PHP1B (G2), and atypical-PHP1B (G3-G5), based on the methylation defect patterns in 4 DMRs on the GNAS locus and etiologies and evaluated the clinical findings in each group and compared them among the groups.

RESULTS

G2 had the youngest age and the highest serum intact parathyroid hormone levels among the 5 groups at the time of diagnosis. The most common symptoms at the time of diagnosis were tetany in G1, and seizures or loss of consciousness in G2. Albright's hereditary osteodystrophy and PHP-suggestive features were most frequently observed in the G2 proband. Nine patients had neurodevelopmental disorders (NDs) consisting of mild to borderline intellectual disability and/or developmental delay. There were no significant correlations between the average methylation ratios of 7 CpG sites in the GNAS-A/B:TSS-DMR and hormonal and biochemical findings.

CONCLUSION

This study revealed the differences in some clinical characteristics, particularly clinical features, and ages at the time of diagnosis between G2 and other groups and detailed NDs observed in some patients with PHP1B.

Serum steroid metabolite profiling by LC-MS/MS in two phenotypic male patients with HSD17B3 deficiency: Implications for hormonal diagnosis

Although 17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) deficiency is diagnosed when a testosterone/androstenedione (T/A-dione) ratio after human chorionic gonadotropin (hCG) stimulation is below 0.8, this cut-off value is primarily based on hormonal data measured by conventional immunoassay (IA) in patients with feminized or ambiguous genitalia. We examined two 46,XY Japanese patients with undermasculinized genitalia including hypospadias (patient 1 and patient 2). Endocrine studies by IA showed well increased serum T value after hCG stimulation (2.91 ng/mL) and a high T/A-dione ratio (4.04) in patient 1 at 2 weeks of age and sufficiently elevated basal serum T value (2.60 ng/mL) in patient 2 at 1.5 months of age. Despite such partial androgen insensitivity syndrome-like findings, whole exome sequencing identified biallelic ″pathogenic″ or ″likely pathogenic″ variants in HSD17B3 (c .188 C>T:p.(Ala63Val) and c .194 C>T:p.(Ser65Leu) in patient 1, and c.139 A>G:p.(Met47Val) and c.672 + 1 G>A in patient 2) (NM_000197.2), and functional analysis revealed reduced HSD17B3 activities of the missense variants (∼ 43% for p.Met47Val, ∼ 14% for p.Ala63Val, and ∼ 0% for p.Ser65Leu). Thus, we investigated hCG-stimulated serum steroid metabolite profiles by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in patient 1 at 7 months of age and in patient 2 at 11 months of age as well as in five control males with idiopathic micropenis aged 1 - 8 years, and found markedly high T/A-dione ratios (12.3 in patient 1 and 5.4 in patient 2) which were, however, obviously lower than those in the control boys (25.3 - 56.1) and sufficiently increased T values comparable to those of control males. The elevated T/A-dione ratios are considered be due to the residual HSD17B3 function and the measurement by LC-MS/MS. Thus, it is recommended to establish the cut-off value for the T/A-dione ratio according to the phenotypic sex reflecting the residual function and the measurement method.

A case of siblings with juvenile retinitis pigmentosa associated with NEK1 gene variants

BACKGROUND

Axial spondylometaphyseal dysplasia(axial SMD) is associated with early-onset retinal dystrophy and various skeletal dysplasias of varying severity. NEK1 is the causative gene for short rib polydactyly syndrome and axial SMD. Here, we report a case of siblings with juvenile retinitis pigmentosa (RP) and NEK1 variants not associated with systemic disorders.

MATERIALS AND METHODS

The patients were a 7-year-old-girl and a 9-year-old boy with RP, who were followed for 9 years. Whole exome sequencing (WES) was performed on the siblings and their parents, who were not consanguineous.

RESULTS

The corrected visual acuity of the girl and the boy at first visit was binocular 20/63 and 20/100 OD and 20/63 OS, respectively. The siblings had narrowing of retinal blood vessels and retinal pigment epithelium atrophy in the fundus and showed an extinguished pattern in electroretinogram. On optical coherence tomography, there was a mottled ellipsoid band with progressive loss in the outer macular, the edges of which corresponded to the ring of hyperautofluorescence on fundus autofluorescence imaging. The siblings showed progressive visual field constriction. Radiological examination did not reveal any skeletal abnormalities. We identified two rare heterozygous NEK1 variants in the patients: c.240 G>A; p.(M80I) and c.634_639dup;p.(V212_L213dup). Heterozygous variants were recognized in the father and mother, respectively. According to the guidelines of the American College of Medical Genetics and Genomics, both variants were classified as likely pathogenic.

CONCLUSION

This is the first report of RP patients with NEK1 variants not associated with skeletal abnormalities.

Microdeletion at ESR1 Intron 6 (DEL_6_75504) Is a Susceptibility Factor for Cryptorchidism and Hypospadias

CONTEXT

We have previously reported that a specific "AGATC" haplotype in a >34 kb tight linkage disequilibrium (LD) block within ESR1 is strongly associated with cryptorchidism and hypospadias in Japanese boys.

OBJECTIVE

We aimed to determine the true susceptibility factor for cryptorchidism and hypospadias linked to the "AGATC" haplotype.

METHODS

We performed various molecular studies in hitherto unreported 230 Italian boys (80 with cryptorchidism and 150 with normal genitalia) and previously reported and newly recruited 415 Japanese boys (149 with cryptorchidism, 141 with hypospadias, and 125 with normal genitalia). We also performed ESR1 expression analyses using breast cancer-derived MCF-7 cells.

RESULTS

Haplotype analysis revealed the LD block and positive association of the "AGATC" haplotype with cryptorchidism in Italian boys. Whole genome sequencing identified an identical 2249-bp microdeletion (ΔESR1) generated by a microhomology-mediated replication error in both Japanese and Italian boys with the specific haplotype. ΔESR1 was found to be strongly associated with cryptorchidism and hypospadias by Cochran-Armitage trend test and was revealed to show nearly absolute LD with the "AGATC" haplotype. ESR1 expression was upregulated in MCF-7 cells with a homozygous deletion encompassing ΔESR1 and those with a homozygous deletion involving a CTCF-binding site within ΔESR1.

CONCLUSION

The results reveal that ΔESR1, which has been registered as "DEL_6_75504" in gnomAD SVs v2.1, is the true susceptibility factor for cryptorchidism and hypospadias. It appears that ΔESR1 was produced in a single ancestral founder of modern humans and has been maintained within the genome of multiple ethnic groups by selection.

Risk assessment of assisted reproductive technology and parental age at childbirth for the development of uniparental disomy-mediated imprinting disorders caused by aneuploid gametes

BACKGROUND

Our previous study suggested that assisted reproductive technology (ART) may be a possible risk factor for the development of epimutation-mediated imprinting disorders (epi-IDs) for mothers aged ≥ 30 years. However, whether ART or advanced parental age facilitates the development of uniparental disomy-mediated IDs (UPD-IDs) has not yet been investigated.

RESULTS

We enrolled 130 patients with aneuploid UPD-IDs including various IDs confirmed by molecular studies and obtained ART data of the general population and patients with epi-IDs from a robust nationwide database and our previous report, respectively. We compared the proportion of ART-conceived livebirths and maternal childbearing age between patients with UPD-IDs and the general population or patients with epi-IDs. The proportion of ART-conceived livebirths in patients with aneuploid UPD-IDs was consistent with that in the general population of maternal age ≥ 30 years and was lower than that in the patients with epi-IDs, although there was no significant difference. The maternal childbearing age of patients with aneuploid UPD-IDs was skewed to the increased ages with several cases exceeding the 97.5th percentile of maternal childbearing age of the general population and significantly higher than that of patients with epi-IDs (P < 0.001). In addition, we compared the proportion of ART-conceived livebirths and parental age at childbirth between patients with UPD-IDs caused by aneuploid oocytes (oUPD-IDs) and that by aneuploid sperm (sUPD-IDs). Almost all ART-conceived livebirths were identified in patients with oUPD-IDs, and both maternal age and paternal age at childbirth were significantly higher in patients with oUPD-IDs than in patients with sUPD-IDs. Because maternal age and paternal age were strongly correlated (r_s = 0.637, P < 0.001), higher paternal age in oUPD-IDs was explained by the higher maternal age in this group.

CONCLUSIONS

Different from the case of epi-IDs, ART itself is not likely to facilitate the development of aneuploid UPD-IDs. We demonstrated that advanced maternal age can be a risk factor for the development of aneuploid UPD-IDs, particularly oUPD-IDs.

Expanded targeted screening for congenital cytomegalovirus infection

An early diagnosis and intervention for congenital cytomegalovirus infection can reduce long-term disability; however, the introduction of universal neonatal screening has been controversial worldwide. The present study clarified the outcome of a targeted screening protocol for detecting congenital cytomegalovirus infection based on suggestive perinatal conditions. In addition, the positive rate was compared to those from the reported studies and the validity of the targeted screening criteria was discussed. A total of 2121 newborn infants were admitted to our hospital between October 2018 and October 2021. Cytomegalovirus DNA was examined by the isothermal nucleic acid amplification method for urine samples from newborns with any of the following: microcephaly, abnormal ultrasound findings in the brain and visceral organs, repeated failure in neonatal hearing screening, suspicious maternal cytomegalovirus infection during pregnancy, and other abnormal findings suggestive of congenital cytomegalovirus infection. Among 2121 newborns, 102 (4.8%) were subject to the urine cytomegalovirus DNA test based on the abovementioned criteria. Of them, three were cytomegalovirus DNA-positive. According to the protocol, the cytomegalovirus DNA-positive rates were 0.14% among the total enrollment of 2121 newborns and 2.9% (3/102) among the targeted newborns. This protocol may overlook congenital cytomegalovirus infection that is asymptomatic or exhibits inapparent clinical manifestations only at birth; however, it is feasible and helps lead to the diagnosis of congenital cytomegalovirus infection that may otherwise be overlooked.

A questionnaire-based survey of medical conditions in adults with Prader-Willi syndrome in Japan: implications for transitional care

Prader-Willi syndrome (PWS) is a multisystem disorder with increased mortality predominantly due to obesity-associated complications; therefore, the management of obesity has been centric to therapeutic strategies for PWS. Although a multidisciplinary team approach has been successful for this purpose during childhood, it is generally difficult to implement during adulthood because of the lack of a structured transitional care program. A more detailed understanding of the current medical conditions of adults with PWS is needed to establish this program; however, limited information is currently available on this issue in Japan. Accordingly, we performed a questionnaire-based survey on 425 patients with PWS. There were 162 adult patients aged 18 years or older with median body mass indexes (kg/m²) of 29.4 and 30.4 in males and females, respectively. The frequencies of type 2 diabetes mellitus (T2DM) and hypertension in adults with PWS were 40.4 and 19.4%, respectively. Growth hormone (GH) therapy during childhood correlated with lower rates of T2DM and hypertension during adulthood. Among adult patients, 54% were treated by pediatricians, whereas 44% were seen by internists with an endocrinologist/diabetologist being the most prevalent. Adult patients treated with GH during childhood showed a higher rate of being seen by pediatricians than those without, demonstrating that the multidisciplinary team approach, typically applied with GH therapy, may be continuously provided even after they reach adulthood. These results emphasize the importance of the seamless provision of the multidisciplinary team approach, which is of clinical importance for establishing an optimal transitional care program for PWS.

Case Report: Molecular autopsy underlie COVID-19-associated sudden, unexplained child mortality

Herein, we report a child with COVID-19 and seemingly no underlying disease, who died suddenly. The autopsy revealed severe anemia and thrombocytopenia, splenomegaly, hypercytokinemia, and a rare ectopic congenital coronary origin. Immunohistochemical analysis demonstrated that the patient had acute lymphoblastic leukemia of the B-cell precursor phenotype (BCP-ALL). The complex cardiac and hematological abnormalities suggested the presence of an underlying disease; therefore, we performed whole-exome sequencing (WES). WES revealed a leucine-zipper-like transcription regulator 1 (LZTR1) variant, indicating Noonan syndrome (NS). Therefore, we concluded that the patient had underlying NS along with coronary artery malformation and that COVID-19 infection may have triggered the sudden cardiac death due to increased cardiac load caused by high fever and dehydration. In addition, multiple organ failure due to hypercytokinemia probably contributed to the patient's death. This case would be of interest to pathologists and pediatricians because of the limited number of NS patients with LZTR1 variants; the complex combination of an LZTR1 variant, BCP-ALL, and COVID-19; and a rare pattern of the anomalous origin of the coronary artery. Thus, we highlight the significance of molecular autopsy and the application of WES with conventional diagnostic methods.

First step towards a consensus strategy for multi-locus diagnostic testing of imprinting disorders

Background

Imprinting disorders, which affect growth, development, metabolism and neoplasia risk, are caused by genetic or epigenetic changes to genes that are expressed from only one parental allele. Disease may result from changes in coding sequences, copy number changes, uniparental disomy or imprinting defects. Some imprinting disorders are clinically heterogeneous, some are associated with more than one imprinted locus, and some patients have alterations affecting multiple loci. Most imprinting disorders are diagnosed by stepwise analysis of gene dosage and methylation of single loci, but some laboratories assay a panel of loci associated with different imprinting disorders. We looked into the experience of several laboratories using single-locus and/or multi-locus diagnostic testing to explore how different testing strategies affect diagnostic outcomes and whether multi-locus testing has the potential to increase the diagnostic efficiency or reveal unforeseen diagnoses.

Results

We collected data from 11 laboratories in seven countries, involving 16,364 individuals and eight imprinting disorders. Among the 4721 individuals tested for the growth restriction disorder Silver–Russell syndrome, 731 had changes on chromosomes 7 and 11 classically associated with the disorder, but 115 had unexpected diagnoses that involved atypical molecular changes, imprinted loci on chromosomes other than 7 or 11 or multi-locus imprinting disorder. In a similar way, the molecular changes detected in Beckwith–Wiedemann syndrome and other imprinting disorders depended on the testing strategies employed by the different laboratories.

Conclusions

Based on our findings, we discuss how multi-locus testing might optimise diagnosis for patients with classical and less familiar clinical imprinting disorders. Additionally, our compiled data reflect the daily life experiences of diagnostic laboratories, with a lower diagnostic yield than in clinically well-characterised cohorts, and illustrate the need for systematising clinical and molecular data.

Clinical and molecular findings in three Japanese patients with N-acetylneuraminic acid synthetase-congenital disorder of glycosylation (NANS-CDG)

We report clinical and molecular findings in three Japanese patients with N-acetylneuraminic acid synthetase-congenital disorder of glycosylation (NANS-CDG). Patient 1 exhibited a unique constellation of clinical features including marked hydrocephalus, spondyloepimetaphyseal dysplasia (SEMD), and thrombocytopenia which is comparable to that of an infant reported by Faye-Peterson et al., whereas patients 2 and 3 showed Camera-Genevieve type SMED with intellectual/developmental disability which is currently known as the sole disease name for NANS-CDG. Molecular studies revealed a maternally inherited likely pathogenic c.207del:p.(Arg69Serfs*57) variant and a paternally derived likely pathogenic c.979_981dup:p.(Ile327dup) variant in patient 1, a homozygous likely pathogenic c.979_981dup:p.(Ile327dup) variant caused by maternal segmental isodisomy involving NANS in patient 2, and a paternally inherited pathogenic c.133-12T>A variant leading to aberrant splicing and a maternally inherited likely pathogenic c.607T>C:p.(Tyr203His) variant in patient 3 (reference mRNA: NM_018946.4). The results, together with previously reported data, imply that (1) NANS plays an important role in postnatal growth and fetal brain development; (2) SMED is recognizable at birth and shows remarkable postnatal evolution; (3) NANS-CDG is associated with low-normal serum sialic acid, obviously elevated urine N-acetylmannosamine, and normal N- and O-glycosylation of serum proteins; and (4) NANS-CDG is divided into Camera-Genevieve type and more severe Faye-Peterson type.

Familial Pseudohypoparathyroidism Type IB Associated with an SVA Retrotransposon Insertion in the GNAS Locus

Loss of methylation (LOM) at GNAS-A/B:TSS-differentially methylated regions (DMRs) in the GNAS locus is observed in pseudohypoparathyroidism type 1B (PHP1B). Many PHP1B cases are sporadic, but autosomal dominant-PHP1B has a deletion involving NESP55 expressed from the maternal allele or STX16 located upstream of the GNAS locus on the maternal allele. We report the possible first familial PHP1B cases with retrotransposon insertion in the GNAS locus on the maternal allele. To our knowledge, they are the possible first cases with imprinting disorders caused by retrotransposon insertion. The two sibling cases experienced tetany and/or cramps from school age and had hypocalcemia and an increased serum intact parathyroid hormone (PTH) level together with overweight, round face, and normal intellectual levels. Methylation analysis for DMRs in the GNAS locus showed only LOM of the GNAS-A/B:TSS-DMR. Copy number abnormalities at STX16 and the GNAS locus were not detected by array comparative genomic hybridization. Whole-genome sequencing and Sanger sequencing revealed an approximately 1000-bp SVA retrotransposon insertion upstream of the first exon of A/B on the GNAS locus in these siblings. Whole-genome methylome analysis by Enzymatic Methyl-Seq in the siblings showed normal methylation status in the region surrounding the insertion site and mild LOM of the GNAS-A/B:TSS-DMR. We conducted transcriptome analysis using mRNA from skin fibroblasts and induced pluripotent stem cells (iPSCs) derived from the siblings and detected no aberrant NESP55 transcripts. Quantitative reverse-transcriptase PCR (qRT-PCR) analysis in skin fibroblasts showed increased A/B expression in the patients and no NESP55 expression, even in a control. qRT-PCR analysis in iPSCs showed decreased NESP55 expression with normal methylation status of the GNAS-NESP:TSS-DMR in the patients. The retrotransposon insertion in the siblings likely caused decreased NESP55 expression that could lead to increased A/B expression via LOM of the GNAS-A/B:TSS-DMR, subsequent reduced Gsα expression, and finally, PHP1B development. © 2022 American Society for Bone and Mineral Research (ASBMR).

Cell death signalling is competitively but coordinately regulated by repressor-type and activator-type ethylene response factors in tobacco (Nicotiana tabacum) plants

Ethylene response factors (ERFs) comprise one of the largest transcription factor families in many plant species. Tobacco (Nicotiana tabacum) ERF3 (NtERF3) and other ERF-associated amphiphilic repression (EAR) motif-containing ERFs are known to function as transcriptional repressors. NtERF3 and several repressor-type ERFs induce cell death in tobacco leaves and are also associated with a defence response against tobacco mosaic virus (TMV). We investigated whether transcriptional activator-type NtERFs function together with NtERF3 in the defence response against TMV infection by performing transient ectopic expression, together with gene expression, chromatin immunoprecipitation (ChIP) and promoter analyses. Transient overexpression of NtERF2 and NtERF4 induced cell death in tobacco leaves, albeit later than that induced by NtERF3. Fusion of the EAR motif to the C-terminal end of NtERF2 and NtERF4 abolished their cell death-inducing ability. The expression of NtERF2 and NtERF4 was upregulated at the early phase of N gene-triggered hypersensitive response (HR) against TMV infection. The cell death phenotype induced by overexpression of wild-type NtERF2 and NtERF4 was suppressed by co-expression of an EAR motif-deficient form of NtERF3. Furthermore, ChIP and promoter analyses suggested that NtERF2, NtERF3 and NtERF4 positively or negatively regulate the expression of NtERF3 by binding to its promoter region. Overall, our results revealed the cell death-inducing abilities of genes encoding activator-type NtERFs, including NtERF2 and NtERF4, suggesting that the HR-cell death signalling via the repressor-type NtERF3 is competitively but coordinately regulated by these NtERFs.

Pathogenic Copy Number and Sequence Variants in Children Born SGA With Short Stature Without Imprinting Disorders

CONTEXT

Children born small-for-gestational-age with short stature (SGA-SS) is associated with (epi)genetic defects, including imprinting disorders (IDs), pathogenic copy number variants (PCNVs), and pathogenic variants of genes involved in growth. However, comprehensive studies evaluating these 3 factors are very limited.

OBJECTIVE

To clarify the contribution of PCNVs and candidate pathogenic variants to SGA-SS.

DESIGN

Comprehensive molecular analyses consisting of methylation analysis, copy number analysis, and multigene sequencing.

METHODS

We enrolled 140 patients referred to us for genetic testing for SGA-SS. Among them, we excluded 42 patients meeting Netchine-Harbison clinical scoring system criteria for Silver-Russell syndrome and 4 patients with abnormal methylation levels of the IDs-related differentially methylated regions. Consequently, we conducted copy number analysis and multigene sequencing for 86 SGA-SS patients with sufficient sample volume. We also evaluated clinical phenotypes of patients with PCNVs or candidate pathogenic variants.

RESULTS

We identified 8 (9.3%) and 11 (12.8%) patients with PCNVs and candidate pathogenic variants, respectively. According to the American College of Medical Genetics standards and guidelines, 5 variants were classified as pathogenic and the remaining 6 variants were classified as variants of unknown significance. Genetic diagnosis was made in 12 patients. All patients with PCNVs or candidate pathogenic variants did not correspond perfectly to characteristic clinical features of each specific genetic cause.

CONCLUSION

We clarified the contribution of PCNVs and pathogenic variants to SGA-SS without IDs. Comprehensive molecular analyses, including copy number analysis and multigene sequencing, should be considered for patients with unknown SGA-SS etiology.

SHOX far-downstream deletion in a patient with nonsyndromic short stature

Haploinsufficiency of SHOX represents one of the major genetic causes of nonsyndromic short stature. To date, eight DNA elements around SHOX exons have been proposed as putative enhancer regions. Although six copy-number variations (CNVs) downstream to the known enhancer regions have recently been identified in patients with short stature, the pathogenicity of these CNVs remains uncertain. Here, we identified a paternally derived SHOX far-downstream deletion in a boy. The deletion involved a ~100 kb genomic interval at a position >60 kb away from the known enhancer regions. The boy exhibited moderate short stature with nonspecific skeletal changes. The height of the father was within the normal range but lower than the mid-parental height. The deletion of the boy and the six previously reported CNVs mostly overlapped; however, all CNVs had unique breakpoints. The deletion of our case encompassed a ~30 kb genomic interval that has previously been associated with a 4C-seq peak, as well as several SHOX-regulatory SNPs/indels. These results indicate that the SHOX far-downstream region contains a novel cis-acting enhancer, whose deletion leads to nonsyndromic short stature of various degree. In addition, our data highlight genomic instability of SHOX-flanking regions that underlies diverse nonrecurrent CNVs.

Trans-acting genetic variants causing multilocus imprinting disturbance (MLID): common mechanisms and consequences

BACKGROUND

Imprinting disorders are a group of congenital diseases which are characterized by molecular alterations affecting differentially methylated regions (DMRs). To date, at least twelve imprinting disorders have been defined with overlapping but variable clinical features including growth and metabolic disturbances, cognitive dysfunction, abdominal wall defects and asymmetry. In general, a single specific DMR is affected in an individual with a given imprinting disorder, but there are a growing number of reports on individuals with so-called multilocus imprinting disturbances (MLID), where aberrant imprinting marks (most commonly loss of methylation) occur at multiple DMRs. However, as the literature is fragmented, we reviewed the molecular and clinical data of 55 previously reported or newly identified MLID families with putative pathogenic variants in maternal effect genes (NLRP2, NLRP5, NLRP7, KHDC3L, OOEP, PADI6) and in other candidate genes (ZFP57, ARID4A, ZAR1, UHRF1, ZNF445).

RESULTS

In 55 families, a total of 68 different candidate pathogenic variants were identified (7 in NLRP2, 16 in NLRP5, 7 in NLRP7, 17 in PADI6, 15 in ZFP57, and a single variant in each of the genes ARID4A, ZAR1, OOEP, UHRF1, KHDC3L and ZNF445). Clinical diagnoses of affected offspring included Beckwith-Wiedemann syndrome spectrum, Silver-Russell syndrome spectrum, transient neonatal diabetes mellitus, or they were suspected for an imprinting disorder (undiagnosed). Some families had recurrent pregnancy loss.

CONCLUSIONS

Genomic maternal effect and foetal variants causing MLID allow insights into the mechanisms behind the imprinting cycle of life, and the spatial and temporal function of the different factors involved in oocyte maturation and early development. Further basic research together with identification of new MLID families will enable a better understanding of the link between the different reproductive issues such as recurrent miscarriages and preeclampsia in maternal effect variant carriers/families and aneuploidy and the MLID observed in the offsprings. The current knowledge can already be employed in reproductive and genetic counselling in specific situations.

Maternal Uniparental Isodisomy of Chromosome 4 and 8 in Patients with Retinal Dystrophy: SRD5A3-Congenital Disorders of Glycosylation and RP1-Related Retinitis Pigmentosa

Purpose: Uniparental disomy (UPD) is a rare chromosomal abnormality. We performed whole-exosome sequencing (WES) in cases of early-onset retinal dystrophy and identified two cases likely caused by UPD. Herein, we report these two cases and attempt to clarify the clinical picture of retinal dystrophies caused by UPD. Methods: WES analysis was performed for two patients and their parents, who were not consanguineous. Functional analysis was performed in cases suspected of congenital disorders of glycosylation (CDG). We obtained clinical case data and reviewed the literature. Results: In case 1, a novel c.57G>C, p.(Trp19Cys) variant in SRD5A3 was detected homozygously. Genetic analysis suggested a maternal UPD on chromosome 4, and functional analysis confirmed CDG. Clinical findings showed early-onset retinal dystrophy, intellectual disability, and epilepsy. In case 2, an Alu insertion (c.4052_4053ins328, p.[Tyr1352Alafs]) in RP1 was detected homozygously. Maternal UPD on chromosome 8 was suspected. The clinical picture was consistent with RP1-related retinitis pigmentosa. Although the clinical features of retinal dystrophy by UPD may vary, most cases present with childhood onset. Conclusions: There have been limited reports of retinal dystrophy caused by UPD, suggesting that it is rare. Genetic counseling may be encouraged in pediatric cases of retinal dystrophy.

Intrauterine hyponutrition reduces fetal testosterone production and postnatal sperm count in the mouse

Although intrauterine hyponutrition is regarded as a risk factor for the development of "testicular dysgenesis syndrome" (TDS) in the human, underlying mechanism(s) remain largely unknown. To clarify the underlying mechanism(s), we fed vaginal plug-positive C57BL/6N female mice with regular food ad libitum throughout the pregnant course (control females) (C-females) or with 50% of the mean daily intake of the C-females from 6.5 dpc (calorie-restricted females) (R-females), and compared male reproductive findings between 17.5-dpc-old male mice delivered from C-females (C-fetuses) and those delivered from R-females (R-fetuses) and between 6-week-old male mice born to C-females (C-offspring) and those born to R-females (R-offspring). Compared with the C-fetuses, the R-fetuses had (1) morphologically normal external genitalia with significantly reduced anogenital distance index, (2) normal numbers of testicular component cells, and (3) significantly low intratesticular testosterone, in association with significantly reduced expressions of steroidogenic genes. Furthermore, compared with the C-offspring, the R-offspring had (1) significantly increased TUNEL-positive cells and normal numbers of other testicular component cells, (2) normal intratesticular testosterone, in association with normal expressions of steroidogenic genes, (3) significantly reduced sperm count, and normal testis weight and sperm motility, and (4) significantly altered expressions of oxidation stress-related, apoptosis-related, and spermatogenesis-related genes. The results, together with the previous data including the association between testosterone deprivation and oxidative stress-evoked apoptotic activation, imply that reduced fetal testosterone production is the primary underlying factor for the development of TDS in intrauterine hyponutrition, and that TDS is included in the clinical spectrum of Developmental Origins of Health and Disease.

Combined pituitary hormone deficiency in a patient with an <i>FGFR1</i> missense variant: case report and literature review

Recent studies have indicated that heterozygous loss-of-function variants in fibroblast growth factor receptor 1 (FGFR1) are involved in the development of congenital hypogonadotropic hypogonadism and combined pituitary hormone deficiency (CPHD). We encountered a Japanese boy with short stature and pubertal failure. Endocrine studies showed GH, TSH, and LH/FSH deficiencies, and brain magnetic resonance imaging delineated hypoplastic anterior pituitary and ectopic posterior pituitary. The patient was treated with GH, l-thyroxine, and hCG/rFSH. Next-generation sequencing panel for pituitary dysfunction identified a probably weak disease-associated heterozygous missense variant in FGFR1 (NM_023110.3:c.176A>T:p.(Asp59Val)), together with a probably non-deleterious heterozygous missense variant in KISS1R (NM_032551.5:c.769G>C:p.(Val257Leu)). We also review six previously reported CHPD patients with probably deleterious FGFR1 variants. The data, in conjunction with the previously reported cases, argue for the relevance of FGFR1 variants to the development of CPHD.

Congenital disorders of estrogen biosynthesis and action

Estrogens regulate pubertal development and reproductive function in women, spermatogenesis in men, and bone turnover and metabolic conditions in individuals of both sexes. Estradiol, the major estrogen in humans, is synthesized from testosterone by the action of aromatase and exerts its effects though binding to estrogen receptors. Germline loss- and gain-of-function variants in CYP19A1, the gene encoding aromatase, lead to aromatase deficiency and aromatase excess syndrome, respectively. Germline loss-of-function variants in ESR1, the gene encoding estrogen receptor α, are known to cause of estrogen insensitivity/resistance. In addition, rare variants in ESR1 and ESR2 have been implicated in various disease phenotypes. Clinical studies on these rare endocrine disorders provided clues to understand the biological functions of estrogens in the human body. This review introduces the genetic basis, phenotypes, and current management procedures of congenital disorders in estrogen biosynthesis and action.

MAMLD1 and Differences/Disorders of Sex Development: An Update

MAMLD1 (alias CXorf6) was first documented in 2006 as a causative gene of 46,XY differences/disorders of sex development (DSD). MAMLD1/Mamld1 is expressed in the fetal testis and is predicted to enhance the expression of several Leydig cell-specific genes. To date, hemizygous MAMLD1 variants have been identified in multiple 46,XY individuals with hypomasculinized external genitalia. Pathogenic MAMLD1 variants are likely to cause genital abnormalities at birth and are possibly associated with age-dependent deterioration of testicular function. In addition, some MAMLD1 variants have been identified in 46,XX individuals with ovarian dysfunction. However, recent studies have raised the possibility that MAMLD1 variants cause 46,XY DSD and ovarian dysfunction as oligogenic disorders. Unsolved issues regarding MAMLD1 include the association between MAMLD1 variants and 46,XX testicular DSD, gene-gene interactions in the development of MAMLD1-mediated DSD, and intracellular functions of MAMLD1.

Cavin-1 modulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

Background

Pulmonary hypertension (PH) is a progressive disease associated with poor outcomes. Caveolin-1 (Cav1) and Cavin-1 are components of caveolae, and Cav1 is identified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is the most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known.

Purpose

Our study aims to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway in pulmonary artery endothelial cells (PAECs). [Methods] Cav1 knockout mice were used to assess PH, and caveolae in PAECs were observed by electron microscope. After knocking down Cav1 and/or Cavin-1 in human PAECs (hPAECs) using siRNA, we evaluated the phosphorylation of Smad by Western blotting. Apoptosis was explored by flow cytometry. To assess the interaction between Cav1 and BMPRII, and the effect of Cavin-1 for this interaction and BMP/Smad signaling, we performed immunoprecipitation, Co-immunostaining, Proximal Ligation Assay (PLA), GST pulldown assay, and Western blotting.

Results

As in previous reports, Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy and PAECs isolated from Cav1 knockout mice showed caveolae disappearance. Cav1 knockdown in hPAECs reduced BMPRII at the plasma membrane and Smad 1/5/9 phosphorylation. Cav1 knockdown also significantly increased hypoxia-induced apoptosis in hPAECs. Co-immunostaining revealed that Cav1 was associated with BMPRII at the membrane of hPAECs. Cavin-1 inhibited the interaction of BMPRII with Cav1 and reduced BMPRII localization on the membrane of hPAECs. GST pulldown assay revealed that Cavin-1 and BMPRII were associated with Cav1 through the scaffolding domain in Cav1. These findings suggest that Cavin-1 and BMPRII are competitively associated with Cav1. Cavin-1 knockdown improved the interaction between Cav1 and BMPRII and inhibited both BMPRII reduction at the plasma membrane and Smad 1/5/9 dephosphorylation.

Conclusions

Cavin-1 affects the interaction of Cav1 with BMPRII at the plasma membrane and modulates BMP/Smad signaling in PAECs. The binding of Cavin-1 to Cav1 enhances the interaction between BMPR2 and Cav1, resulting in stabilization of BMPRII localization at the plasma membrane in PAECs and prevention of BMP/Smad signaling attenuation, which is important for PAH development.

Funding Acknowledgement

Type of funding sources: None.

Human Spermatogenesis Tolerates Massive Size Reduction of the Pseudoautosomal Region

Mammalian male meiosis requires homologous recombination between the X and Y chromosomes. In humans, such recombination occurs exclusively in the short arm pseudoautosomal region (PAR1) of 2.699 Mb in size. Although it is known that complete deletion of PAR1 causes spermatogenic arrest, no studies have addressed to what extent male meiosis tolerates PAR1 size reduction. Here, we report two families in which PAR1 partial deletions were transmitted from fathers to their offspring. Cytogenetic analyses revealed that a ∼400-kb segment at the centromeric end of PAR1, which accounts for only 14.8% of normal PAR1 and 0.26% and 0.68% of the X and Y chromosomes, respectively, is sufficient to mediate sex chromosomal recombination during spermatogenesis. These results highlight the extreme recombinogenic activity of human PAR1. Our data, in conjunction with previous findings from animal studies, indicate that the minimal size requirement of mammalian PARs to maintain male fertility is fairly small.

Treatment approaches for congenital transverse limb deficiency: Data analysis from an epidemiological national survey in Japan

BACKGROUND

Congenital limb deficiency is a rare anomaly that impairs limb function. Transverse deficiency accounts for approximately half of congenital limb deficiency cases. In Japan, there have been no detailed data of clinical features, especially treatment approaches, of this disorder. The present study aimed to investigate the status of treatment approaches of congenital transverse limb deficiency in Japan.

METHODS

From the national epidemiological survey of congenital limb deficiency undertaken in Japan in 2016, all the data of 200 patients with congenital transverse limb deficiencies were extracted. These data were analysed to reveal the treatment approaches of congenital transverse limb deficiency and its basic clinical features.

RESULTS

Surgical treatments and prosthetic or orthotic intervention had been implemented or planned for about one-quarter of patients, respectively. In the upper limb deficiencies, prosthetic or orthotic intervention was likely chosen in cases of deficiency at the metacarpal or proximal to metacarpal level. Surgical treatment was chosen only in cases of deficiency at the carpal or distal to carpal level. Although the number of patients with transverse lower limb deficiencies was small, prosthetic or orthotic intervention was likely chosen in proximal deficiencies, and surgical treatment was likely chosen in distal deficiencies.

CONCLUSIONS

Herein, we revealed the status of treatment approaches for congenital transverse limb deficiency in Japan. Approximately half of the patients had no history of-and no plans for-surgical, prosthetic, or orthotic interventions. Further treatment advances may enable patients with congenital limb deficiencies to increase their participation in daily activities.

STUDY DESIGN

Cross-sectional survey.

The use of ultrasound in central vascular ligation during laparoscopic right-sided colon cancer surgery: technical notes

BACKGROUND

Complete mesocolic excision (CME) with central vascular ligation (CVL) requires the surgeon to sharply dissect the mesocolon and approach the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) for ligation of the supplying vessels relating to right-sided colon cancer at their origin. Even with preoperative images, it can still be challenging to identify these structures during laparoscopic surgery because of various intraoperative conditions. The aim of this study was to assess the efficacy of intraoperative ultrasound (IOUS) for identification of blood vessels during right-sided colon cancer surgery.

METHODS

We performed IOUS on 19 patients diagnosed with right-sided colon cancer at our institution, in January-October 2020. Preoperatively, a three-dimensional computed tomography (3D-CT) angiogram was obtained for the majority of patients to visualize the SMA, SMV, and their respective branches. The running position of the ileocolic artery (ICA) and right colic artery (RCA) related to the SMV and the presence of the middle colic artery were identified and compared using preoperative 3D-CT, IOUS, and intraoperative findings.

RESULTS

Nineteen patients [seven men and 12 women with a mean age of 73.9 ± 8.4 years (range 58-82 years)] were studied, including some with a body mass index of > 30 kg/m², locally advanced cancer, and severe adhesion. There were IOUSs that detected the SMA, SMV, and their tributaries in all patients. The positional relationships between the SMV and the ICA and RCA revealed by IOUS were consistent with the preoperative and intraoperative findings.

CONCLUSION

IOUS is a safe, feasible, and reproducible technique that can assist in detecting the branching of the SMA and SMV during CME with CVL in laparoscopic right-sided colon cancer surgery, regardless of individual conditions.

Primary ovarian insufficiency in a female with phosphomannomutase-2 gene (PMM2) mutations for congenital disorder of glycosylation

Primary ovarian insufficiency (POI) is a highly heterogeneous condition, and its underlying causes remain to be clarified in a large fraction of patients. Congenital disorders of glycosylation (CDG) are multisystem diseases caused by mutations of a number of genes involved in N-glycosylation or O-glycosylation, and the most frequent form is PMM2-CDG (alias, CDG-Ia) resulting from biallelic mutations in PMM2 encoding phosphomannomutase-2 involved in N-glycosylation. Here, we examined a 46,XX Japanese female with syndromic POI accompanied by an undetectable level of serum anti-Müllerian hormone (AMH). Whole exome sequencing identified biallelic pathogenic mutations of PMM2 (a novel c.34G>C:p.(Asp12His) of maternal origin and a recurrent c.310C>G:p.(Leu104Val) of paternal origin) (NM_000303.3), and N-glycosylation studies detected asialotransferrin and disialotransferrin characteristic of PMM2-CDG, in addition to normally glycosylated tetrasialotransferrin. Clinical assessment showed cerebellar hypotrophy, which is a fairly characteristic and highly prevalent feature in PMM2-CDG, together with multiple non-specific features reported in PMM2-CDG such as characteristic face, intellectual disability, skeletal abnormalities, and low blood antithrombin III value. These results including the undetectable level of serum AMH, in conjunction with previously reported findings suggestive of the critical role of glycosylation in oocyte development and function, imply that PMM2-CDG almost invariably leads to POI primarily because of the defective oogenesis and/or oocyte-dependent early folliculogenesis rather than the compromised bioactivity of FSH/LH with defective glycosylation. Thus, it is recommended to examine PMM2 in patients with syndromic POI, especially in those with cerebellar ataxia/hypotrophy.

ZNF445: a homozygous truncating variant in a patient with Temple syndrome and multilocus imprinting disturbance

Background

ZNF445, as well as ZFP57, is involved in the postfertilization methylation maintenance of multiple imprinting-associated differentially methylated regions (iDMRs). Thus, ZNF445 pathogenic variants are predicted to cause multilocus imprinting disturbances (MLIDs), as do ZFP57 pathogenic variants. In particular, the MEG3/DLK1:IG-DMR would be affected, because the postzygotic methylation imprint of the MEG3/DLK1:IG-DMR is maintained primarily by ZNF445, whereas that of most iDMRs is preserved by both ZFP57 and ZNF445 or primarily by ZFP57.

Results

We searched for a ZNF445 variant(s) in six patients with various imprinting disorders (IDs) caused by epimutations and MLIDs revealed by pyrosequencing for nine iDMRs, without a selection for the original IDs. Re-analysis of the previously obtained whole exome sequencing data identified a homozygous ZNF445 variant (NM_181489.6:c.2803C>T:p.(Gln935*)) producing a truncated protein missing two of 14 zinc finger domains in a patient with Temple syndrome and MLID. In this patient, array-based genomewide methylation analysis revealed severe hypomethylation of most CpGs at the MEG3:TSS-DMR, moderate hypomethylation of roughly two-thirds of CpGs at the H19/IGF2:IG-DMR, and mild-to-moderate hypomethylation of a few CpGs at the DIRAS3:TSS-DMR, MEST:alt-TSS-DMR, IGF2:Ex9-DMR, IGF2:alt-TSS, and GNAS-AS1:TSS-DMR. Furthermore, bisulfite sequencing analysis for the MEG3/DLK1:IG-DMR delineated a markedly hypomethylated segment (CG-A). The heterozygous parents were clinically normal and had virtually no aberrant methylation pattern.

Conclusions

We identified a ZNF445 pathogenic variant for the first time. Since ZNF445 binds to the MEG3/DLK1:IG-DMR and other iDMRs affected in this patient, the development of Temple syndrome and MLID would primarily be explained by the ZNF445 variant. Furthermore, CG-A may be the target site for ZNF445 within the MEG3/DLK1:IG-DMR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01106-5.

Long-Term Effect of Aromatase Inhibition in Aromatase Excess Syndrome

Aromatase excess syndrome (AEXS) is a very rare disorder characterized by prepubertal gynecomastia, bone age acceleration and early growth arrest. Heterozygote submicroscopic rearrangements within the promotor of CYP19A1 result in overexpression of aromatase and enhanced aromatization of androgens. Long-term treatment effects of aromatase inhibitors are unknown. Retrospectively we collected data from file records of 7 boys (three sibling pairs and one sporadic case) with AEXS. Genetic analysis revealed upstream of CYP19A1 a 165,901 bp deletion in 4 German cousins, a 198,662 bp deletion in 2 Japanese brothers and a 387,622 bp tandem duplication in a Japanese boy. All boys developed prepubertal gynecomastia, at 9.0 yr of age (median; range: 7.0 - 11.0). Height was +1.20 SDS (-0.24 - +1.98); predicted adult height was -1.29 (-3.29 - +1.09 SDS). Four boys were treated with anastrozole 1.0 mg daily, while three reached adult height untreated. Treatment with anastrozole was stopped after 5.6 yr (4.0 - 6.8). Three treated boys exceeded height prognosis by 2.4, 6.9 and 8.1 cm; while one untreated fell below prognosis by 8.6 cm. One treated with a low dose and two untreated reached their prognosis. Adult heights were -0.91 SDS with anastrozole (-2.86 - -0.29) and -0.15 SDS without (-2.31 - -0.03). Distance to target height was -0.22 SDS with anastrozole (-1.72 - +0.52) and +0.54 SDS without treatment (+0.23 - +1.30). Spontaneous growth in AEXS varied, even in the same family. Our data suggest that early started, long-term inhibition by aromatase inhibitor anastrozole (1 mg daily) promotes adult height in boys with AEXS.

Long-term Effect of Aromatase Inhibition in Aromatase Excess Syndrome

CONTEXT

Aromatase excess syndrome (AEXS) is a very rare disorder characterized by prepubertal gynecomastia, bone age acceleration, and early growth arrest. Heterozygote submicroscopic rearrangements within the promotor of CYP19A1 result in overexpression of aromatase and enhanced aromatization of androgens.

OBJECTIVE

The objective was to study long-term treatment effects of an aromatase inhibitor.

METHODS

Data from 7 boys with AEXS were retrospectively collected. Genetic analysis revealed upstream of CYP19A1 a 165 901 bp deletion in 4 German cousins, a 198 662 bp deletion in 2 Japanese brothers, and a 387 622 bp tandem duplication in a Japanese boy.

RESULTS

All boys developed prepubertal gynecomastia, at median 9.0 years of age (range: 7.0-11.0). Height was +1.20 standard deviation score (SDS) (-0.24 to +1.98); predicted adult height was -1.29 SDS (-3.29 to +1.09). Four boys were treated with 1.0 mg of anastrozole daily, while 3 reached adult height untreated. Treatment with anastrozole was stopped after 5.6 years (4.0-6.8). Three treated boys exceeded their prognosis by 2.4, 6.9, and 8.1 cm, while 1 untreated boy fell below the prognosis by 8.6 cm. One treated with a low dose and 2 untreated reached their prognosis. Adult heights were -0.91 SDS with anastrozole (-2.86 to -0.29) and -0.15 SDS without (-2.31 to -0.03). Distance to target height was -0.22 SDS with anastrozole (-1.72 to +0.52) and +0.54 SDS without (+0.23 to +1.30).

CONCLUSION

Spontaneous growth in AEXS varied, even in the same family. Our data suggest that early started, long-term inhibition by anastrozole promotes adult height in boys with AEXS.

Parthenogenetic mosaicism: generation via second polar body retention and unmasking of a likely causative PER2 variant for hypersomnia

Background

Parthenogenetic mosaicism is an extremely rare condition identified only in five subjects to date. The previous studies indicate that this condition is mediated by parthenogenetic activation and is free from a specific phenotype ascribed to unmaking of a maternally inherited recessive variant in the parthenogenetic cell lineage.

Results

We examined a 28-year-old Japanese 46,XX female with Silver-Russell syndrome and idiopathic hypersomnia. The results revealed (1) predominance of maternally derived alleles for all the differentially methylated regions examined; (2) no disease-related copy-number variant; (3) two types of regions for all chromosomes, i.e., four BAF (B-allele frequency) band regions with single major microsatellite peaks of maternal origin and single minor microsatellite peaks of non-maternal (paternal) origin, and six BAF band regions with single major microsatellite peaks of maternal origin and two minor microsatellite peaks of maternal and non-maternal (paternal) origin; (4) an unmasked extremely rare PER2 variant (c.1403G>A:p.(Arg468Gln)) with high predicted pathogenicity; (5) mildly affected local structure with altered hydrogen bonds of the p.Arg468Gln-PER2 protein; and (6) nucleus-dominant subcellular distribution of the p.Arg468Gln-PER2 protein.

Conclusions

The above findings imply that the second polar body retention occurred around fertilization, resulting in the generation of the parthenogenetic cell lineage by endoreplication of a female pronucleus and the normal cell lineage by fusion of male and female pronuclei, and that the homozygous PER2 variant in the parthenogenetic cells is the likely causative factor for idiopathic hypersomnia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01062-0.