Silver-Russell Syndrome Patients Research Articles

Anesthesia experience in an adult Silver-Russell syndrome: a case report

BackgroundThere are no reports of anesthesia use in adult patients with Silver-Russell syndrome (SRS). Here, we report our experience with anesthesia in an adult patient with SRS complicated by chronic respiratory failure.Case presentationA 33-year-old woman was clinically diagnosed with SRS. She had severe chronic respiratory failure, complicated by superior mesenteric artery syndrome. Percutaneous gastrostomy was scheduled for nutritional management under epidural anesthesia; however, soon after esophagogastroduodenoscopy was started, she lost consciousness and spontaneous respiration. The patient was urgently intubated and converted to general anesthesia. The end-tidal carbon dioxide tension was > 90 mmHg at intubation.ConclusionsAdult SRS patients with chronic respiratory failure have a risk of CO2 narcosis. SRS also requires preparation for difficult airway management during the perioperative period.

Characterization of HMGA2 variants expands the spectrum of Silver-Russell syndrome.

Silver-Russell syndrome (SRS) is a heterogeneous disorder characterized by intrauterine and postnatal growth retardation. HMGA2 variants are a rare cause of SRS and its functional role in human linear growth is unclear. Patients with suspected SRS negative for 11p15LOM/mUPD7 underwent whole-exome and/or targeted-genome sequencing. Mutant HMGA2 protein expression and nuclear localization were assessed. Two Hmga2-knockin mouse models were generated. Five clinical SRS patients harbored HMGA2 variants with differing functional impacts: 2 stop-gain nonsense variants (c.49G>T, c.52C>T), c.166A>G missense variant, and 2 frameshift variants (c.144delC, c.145delA) leading to an identical, extended-length protein. Phenotypic features were highly variable. Nuclear localization was reduced/absent for all variants except c.166A>G. Homozygous knockin mice recapitulating the c.166A>G variant (Hmga2K56E) exhibited a growth-restricted phenotype. An Hmga2Ter76-knockin mouse model lacked detectable full-length Hmga2 protein, similarly to patient 3 and 5 variants. These mice were infertile, with a pygmy phenotype. We report a heterogeneous group of individuals with SRS harboring variants in HMGA2 and describe the first Hmga2 missense knockin mouse model (Hmga2K56E) to our knowledge causing a growth-restricted phenotype. In patients with clinical features of SRS but negative genetic screening, HMGA2 should be included in next-generation sequencing testing approaches.

The effects of 3-year growth hormone treatment and body composition in Polish patients with Silver-Russell syndrome.

Silver-Russell syndrome (SRS) is characterized by clinical and genetic heterogeneity. SRS is the only disease entity associated with (epi)genetic abnormalities of 2 different chromosomes: 7 and 11. In SRS, the 2 most frequent molecular abnormalities are hypomethylation (loss of methylation) of region H19/IGF2:IG-DMR on chromosome 11p15.5 (11p15 LOM) and maternal uniparental disomy of chromosome 7 (upd(7)mat). Therapy with recombinant human growth hormone (rhGH) is implemented to increase body height in children with SRS. The effect of the administered rhGH on height, weight, body mass index (BMI), body composition, and height velocity in patients with SRS during 3 years of rhGH therapy was analysed. 31 SRS patients (23 with 11p15 LOM, 8 with upd(7)mat) and 16 patients small for gestational age (SGA) as a control group were diagnosed and followed up in The Children's Memorial Health Institute. Patients were eligible for the 2 Polish rhGH treatment programmes [for patients with SGA or with growth hormone deficiency (GHD)]. Anthropometric parameters were collected in all patients. Body composition using bioelectrical impedance was measured in 13 SRS and 14 SGA patients. Height, weight, and weight for height (SDS) at baseline of rhGH therapy were lower in SRS patients than in the SGA control group: -3.3 ± 1.2 vs. -2.6 ± 06 (p = 0.012), -2.5 vs. -1.9 (p = 0.037), -1.7 vs. -1.1 (p = 0.038), respectively. Height SDS was increased from -3.3 ± 1.2 to -1.8 ± 1.0 and from -2.6 ± 0.6 to -1.3 ± 0.7 in the SRS and SGA groups, respectively. Patients with 11p15 LOM and upd(7) mat achieved similar height, 127.0 ± 15.7 vs. 128.9 ± 21.6 cm, and -2.0 ± 1.3 vs. -1.7 ± 1.0 SDS, respectively. Fat mass percentage decreased in SRS patients from 4.2% to 3.0% (p < 0.05) and in SGA patients from 7.6% to 6.6% (p < 0.05). Growth hormone therapy has a positive influence on the growth of SRS patients. Regardless of molecular abnormality type (11p15 LOM vs. upd(7)mat), height velocity was similar in SRS patients during 3 years of rhGH therapy.

Pubertal timing in children with Silver Russell syndrome compared to those born small for gestational age.

ContextData on pubertal timing in Silver Russell syndrome (SRS) are limited.Design and methodsRetrospective observational study including twenty-three SRS patients [11p15 loss of methylation, (11p15 LOM, n=10) and maternal uniparental disomy of chromosome 7 (mUPD7, n=13)] and 21 small for gestational age (SGA). Clinical (thelarche in females; testis volume ≥ 4 ml in males; pubarche), BMI SD trend from the age of 5 to 9 years to the time of puberty, biochemical parameters of puberty onset [Luteinizing hormone (LH), 17-β-estradiol, testosterone], and bone age progression were evaluatedResultsPubertal onset and pubarche occurred significantly earlier in children with SRS than in SGA (p 0.03 and p 0.001, respectively) and clinical signs of puberty onset occurred earlier in mUPD7 than in 11p15LOM group (p 0.003). Five SRS children experienced central precocious puberty and LH, 17-β-estradiol, testosterone were detected earlier in SRS than in SGA (p 0.01; p 0.0001). Bone age delay in SRS children was followed by rapid advancement; the delta between bone age and chronological age in SRS group became significantly higher than in SGA group at the age of 9-11 years (p 0.007). 11p15LOM patients were underweight at the age of 5 years and showed a progressive normalization of BMI that was significantly higher than in mUPD7 (p 0.04) and SGA groups (p 0.03) at puberty onset.ConclusionTiming of puberty is affected in SRS and occurred earlier in mUPD7 compared to 11p15LOM. The impact of early puberty on adult height and metabolic status deserves long-term evaluation.

The Methylation Status in the Chromosome 11p15.5 Region and Metabolic Disorders in Children with Syndromic and Nonsyndromic Intrauterine Growth Restriction

Loss of methylation (LoM) of the imprinting control region 1 (ICR1) in the chromosome 11p15.5 domain is detected in patients with Silver-Russell syndrome (SRS), characterized by asymmetric pre- and postnatal growth restriction, and typical craniofacial features. The patients with intrauterine growth restriction (IUGR) possess a high risk for adult metabolic problems. This study is aimed to investigate the methylation levels of the chromosome 11p15.5 region and metabolic problems in children with syndromic and nonsyndromic IUGR. Methylation analysis was performed for chromosome 11p15.5 in 49 patients (33 with suspected SRS and 16 nonsyndromic IUGR) with Netchine-Harbison clinical scoring (NHCS); uniparental disomy for chromosomes 6, 7, 14, and 20 was evaluated for those who were negative. LoM of ICR1 was detected in 14 of 33 suspected SRS patients with 3 or more criteria of NHCS, 5 had borderline LoM. Maternal uniparental disomy of the chromosomes 7 and 14 was found in 2 patients. The overall detection rate of SRS was 45.5%. While clinical findings were similar in patients with LoM and borderline LoM of ICR1, typical craniofacial findings were significantly less in the patients with normal methylation. Methylation patterns were not found to be impaired in the nonsyndromic IUGR group. Metabolic complications were evaluated in a total of 63 patients including 33 SRS-suspicious, 16 nonsyndromic IUGR, and 14 patients with 3M or SHORT syndrome. Increased rates of hypercalciuria, insulin resistance, and dyslipidemia were detected in patients with both syndromic and nonsyndromic IUGR. We would like to emphasize that detecting typical facial findings is effective in the diagnosis of SRS and paying attention to metabolic problems in the follow-up of patients with IUGR is recommended.

Limb Lengthening in Russell-Silver Syndrome: An Update Confirming Safe and Speedy Healing.

Russell-Silver syndrome (RSS) is a unique cause of syndromic, and often severe, limb length discrepancy (LLD). RSS causes growth retardation both in utero and postnatally, with asymmetry in limb length more noticeable as growth progresses throughout childhood and adolescent. We aim to present the largest cohort in the literature on limb lengthening in patients with RSS and to validate previous literature supporting faster bony consolidation in these patients with more robust data. We further aim to establish differences in healing within this cohort based on age, sex, segment lengthened, or type of lengthening procedure performed, to help refine patient expectations and guide practitioners in treating this population. This was a retrospective study of patients with a diagnosis of RSS who underwent a limb lengthening procedure for the purpose of limb equalization. They were compared with a historic control group of patients who underwent limb lengthening for LLD of a non-RSS etiology. The primary outcome measure was bone healing index (BHI). The RSS group consisted of 24 patients with 29 segments lengthened, and was compared with a historic control group consisting of 20 patients with 22 segments lengthened (Goldman). Patients with RSS had a significantly lower BHI, and therefore faster healing of their lengthening site, than their non-RSS peers (P=0.02). Within the RSS cohort, we did not detect a difference in BHI based on intervention type or sex, but we did find a trend toward faster healing in femurs over tibiae (P=0.08), and established that younger patients tended toward lower BHIs (P<0.01). Our results confirmed with more robust data the prior finding that patients with RSS may undergo limb lengthening procedures at least as safely as their non-RSS counterparts, and with even faster bony consolidation, especially in younger patients. We hypothesize that concurrent treatment with growth hormone supplementation may contribute to this finding, although further study is necessary. This is the largest cohort of RSS patients treated with limb lengthening for LLD reported in the literature, and these findings will help to guide surgeon decision-making when treating this unique population. Level III-retrospective comparative study.

Cognitive profiles and brain volume are affected in patients with Silver–Russell syndrome

Silver–Russell syndrome (SRS) is a rare condition associated with pre and postnatal growth retardation. The most common causes of SRS are 11p15 ICR1 loss of methylation (LOM) and maternal uniparental disomy of chromosome 7 (mUPD7). Almost all patients with SRS have a history of intrauterine growth retardation (IUGR) and may be born small for gestational age (SGA). Children with SRS show typical features, including relative macrocephaly, prominent forehead, body asymmetry, feeding difficulties and cognitive delay (1)(2). SRS patients with 11p15 LOM show high IGF1 levels suggestive of IGF1 insensitivity. IGF1 is implicated in brain development, in particular with neural proliferation and cognitive function (2)(3).

Molecular characterization of temple syndrome families with 14q32 epimutations

Temple Syndrome (TS14) is an imprinting disorder caused by molecular disruptions of the imprinted region in 14q32 (MEG3:TSS-DMR). The frequency of the three known TS14 subtypes (deletions, maternal uniparental disomy (upd(14)mat), loss of methylation (LOM)) is currently in discussion, and within the LOM group, the occurrence of Multilocus Imprinting Disturbances (MLID) has been identified. We present 16 TS14 patients with molecular alterations affecting the MEG3:TSS-DMR, comprising seven patients (43.8%) with LOM, six carriers with upd(14)mat (37.5%), and three cases (18.8%) with a deletion affecting the paternal MEG3:TSS-DMR. We did not find any evidence for MLID in the LOM group, including two cases in which different tissues were available. Whole exome sequencing (WES) in the MEG3:TSS-DMR LOM patients and their parents (Trio WES) did not reveal an obvious pathogenic variant which might cause aberrant methylation at imprinted loci. By summarizing our data with those from the literature, we could show that MLID affecting clinically relevant imprinted loci is rare in TS14 and therefore differs markedly from other imprinting disorders associated with MLID, e.g. Silver-Russell syndrome (SRS) and Beckwith-Wiedemann syndrome (BWS). However, consistent with the clinical overlap with TS14, in SRS patients carrying MLID the MEG3:TSS-DMR is frequently affected. Variants in the known candidate genes for maternal effect variants causing MLID and fetal MLID determinants could not be identified in TS14 patients. Thus, 14q32 epimutations probably have other molecular causes than epimutations in BWS or SRS patients.

Assisted reproductive technology represents a possible risk factor for development of epimutation-mediated imprinting disorders for mothers aged \u2265 30\u2009years

BackgroundsThe proportion of assisted reproductive technology (ART)-conceived livebirths of patients with imprinting disorders (IDs) is higher than that of the general population. Whether this is due to ART or confounding effects of advanced parental age was not investigated. We examined the association of ART and parental ages at childbirth for the development of eight epimutation-mediated imprinting disorders (epi-IDs).ResultsWe enrolled 136 patients with epi-IDs and obtained general population ART data from the Japanese robust nationwide registry. We compared the proportion of ART-conceived livebirths and maternal childbearing ages between patients with epi-IDs and the general population. The proportion of ART-conceived livebirths in patients with epi-IDs was higher than that in mothers aged ≥ 30 years, the age group in which more than 90% of ART procedures performed. The maternal childbearing ages of patients with epi-IDs were widely distributed from 19 to 45 (median: 32) within the approximate 2.5th to 97.5th percentiles of maternal childbearing ages of the general population. In addition, we compared the proportion of ART-conceived livebirths and parental ages at childbirth across patients with eight epi-IDs. We demonstrated that more than 90% of ART-conceived patients with epi-IDs were found in Silver-Russell syndrome (SRS) and Beckwith-Wiedemann syndrome (BWS) patients, and parental ages were almost consistent in patients with eight epi-IDs, except Prader-Willi syndrome.ConclusionsAccording to the prerequisite that most of the ART procedures in Japan are performed on mothers aged ≥ 30 years, ART can be a risk factor for the development of epi-IDs, particularly SRS and BWS, for mothers aged ≥ 30 years.

Successful generation of epigenetic disease model mice by targeted demethylation of the epigenome

BackgroundEpigenetic modifications, including DNA methylation, play an important role in gene silencing and genome stability. Consequently, epigenetic dysregulation can cause several diseases, such as cancer, obesity, diabetes, autism, and imprinting disorders.ResultsWe validate three methods for the generation of epigenome-edited mice using the dCas9-SunTag and single-chain variable fragment-TET1 catalytic domain. We generate model mice for Silver-Russell syndrome (SRS), an imprinting disorder, by target-specific DNA demethylation in the H19 differentially methylated region. Like SRS patients, these mice show H19 upregulation and Igf2 downregulation, leading to severe intrauterine and postnatal growth retardation.ConclusionThis is the first report of an imprinting disease model animal generated by targeted demethylation of specific loci of the epigenome in fertilized eggs. Epigenome-edited animals are also useful for exploring the causative epimutations in epigenetic diseases.

Novel genetic defects in a cohort of Silver-Russell Syndrome (SRS) and SRS-like patients

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Cognitive Profiles and Brain Volume Are Affected in Patients with Silver-Russell Syndrome.

There is little information on cognitive function in Silver-Russell syndrome (SRS), and no neuroimaging studies are available so far. To assess cognitive function and brain volumes in patients with SRS. Wechsler Intelligence Scale and brain magnetic resonance on a 3-Tesla scanner with Voxel-based morphometry analysis were performed between 2016 and 2018 in a single tertiary university center. 38 white subjects with clinical diagnosis of SRS confirmed by molecular analysis: 30 of these patients (mean age 12.6 ± 10 years) were enrolled for cognitive assessment; 23 of the 30 performed neuroimaging sequences. A control group of 33 school-aged children performed cognitive assessment while 65 age and sex-matched volunteers were included for the neuroradiological assessment. Intelligence quotient, Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI), Processing Speed Index, and brain volume. The mean overall IQ score was 87.2 ± 17, and it was significantly lower in the maternal uniparental disomy of chromosome 7 (mUPD7) group at the age of 6 to 16 years compared to loss of methylation on chromosome 11p15 (11p15 LOM) group and to controls. VCI, PRI, and WMI were significantly higher in 11p15 LOM group and in control group than in mUPD7 group at the age of 6 to 16 years. There were no significant differences in cognitive scores between 11p15 LOM school-aged patients and the control group. SRS patients showed lower brain volume compared to controls at the frontal/temporal poles and globi pallidi. Patients with mUPD7 had an impaired cognitive profile. The brain volume at the frontal/temporal lobes and at the globi pallidi was reduced in patients with SRS.

Molecular Etiology Disclosed by Array CGH in Patients With Silver-Russell Syndrome or Similar Phenotypes.

Introduction: Silver–Russell syndrome (SRS) is an imprinting disorder primarily caused by genetic and epigenetic aberrations on chromosomes 11 and 7. SRS is a rare growth retardation disorder often misdiagnosed due to its heterogeneous and non-specific clinical features. The Netchine–Harbison clinical scoring system (NH-CSS) is the recommended tool for differentiating patients into clinical SRS or unlikely SRS. However, the clinical diagnosis is molecularly confirmed only in about 60% of patients, leaving the remaining substantial proportion of SRS patients with unknown genetic etiology. Materials and Methods: A cohort of 34 Italian patients with SRS or SRS-like features scored according to the NH-CSS and without any SRS-associated (epi)genetic alterations was analyzed by high-resolution array-based comparative genomic hybridization (CGH) in order to identify potentially pathogenic copy number variants (CNVs). Results and Discussion: In seven patients, making up 21% of the initial cohort, five pathogenic and two potentially pathogenic CNVs were found involving distinct genomic regions either previously associated with growth delay conditions (1q24.3-q25.3, 17p13.3, 17q22, and 22q11.2-q11.22) and with SRS spectrum (7p12.1 and 7p15.3-p14.3) or outlined for the first time (19q13.42), providing a better definition of reported and as yet unreported SRS overlapping syndromes. All the variants involve genes with a defined role in growth pathways, and for two genes mapping at 7p, IGF2BP3 and GRB10, the association with SRS turns out to be reinforced. The deleterious effect of the two potentially pathogenic variants, comprising GRB10 and ZNF331 genes, was explored by targeted approaches, though further studies are needed to validate their pathogenic role in the SRS etiology. In conclusion, we reconfirm the utility of performing a genome-wide scan to achieve a differential diagnosis in patients with SRS or similar features and to highlight novel chromosome alterations associated with SRS and growth retardation disorders.

Gonadal function and pubertal development in patients with Silver-Russell syndrome

STUDY QUESTION: Is gonadal function affected in males and females with Silver-Russell Syndrome (SRS)?SUMMARY ANSWER: Sertoli cell dysfunction is more common in males with SRS, with 11p15 LOM, but gonadal function seems to be unaffected in females with SRS.WHAT IS KNOWN ALREADY: Males with SRS have an increased risk for genital abnormalities such as cryptorchidism and hypospadias, which could be associated with reproductive problems in later life. In SRS females, an association has been described with Mayer-Rokitansky-Kuster-Hauser syndrome, which might compromise their reproductive function.STUDY DESIGN, SIZE, DURATION: Longitudinal follow-up study, involving 154 subjects, over a time period of 20 years.PARTICIPANTS/MATERIALS, SETTING, METHODS: Thirty-one SRS patients (14 males) and 123 non-SRS patients born at same gestational age (SGA; 65 males). All received growth hormone and 27.3% received additional gonadotropin-releasing hormone analog treatment (GnRHa).MAIN RESULTS AND THE ROLE OF CHANCE: Mean age at onset of puberty was 11.5 years in SRS males versus 11.6 years in non-SRS males (P = 0.51), and 10.5 years in SRS females versus 10.7 years in non-SRS females (P = 0.50). Four of the 14 SRS males had a post-pubertal inhibin-B level below the fifth percentile compared to healthy controls, and two of them an FSH above the 95th percentile, indicating Sertoli cell dysfunction. One of them had a history of bilateral cryptorchidism and orchiopexy. All SRS females had AMH, LH and FSH levels within the reference range. Pubertal duration to Tanner stage five was similar in SRS and non-SRS. Pubertal height gain was better in SRS patients who additionally received GnRHa (P < 0.01). Mean age at menarche was 13.1 years in SRS versus 13.3 years in non-SRS (P = 0.62). One SRS female had primary amenorrhea due to Mullerian agenesis.LIMITATIONS, REASONS FOR CAUTION: As this is a rare syndrome, the SRS group had a small size.WIDER IMPLICATIONS OF THE FINDINGS: As gonadal function is not affected in females with SRS, it is likely that reproductive function is also not affected. Sertoli cell dysfunction in males with SRS could cause impaired reproductive function and should be assessed during pubertal development.STUDY FUNDING/COMPETING INTEREST(S): No external funding was used for the study. The authors have no conflicts of interest.

Sleep disordered breathing in Silver−Russell syndrome patients: a new outcome

ObjectiveImprinting disorders (ID), such as Prader–Willi syndrome (PWS), are associated with sleep-disordered breathing (SDB). No data are available for Silver−Russell syndrome (SRS), another ID that shares clinical features with PWS, although many patients describe excessive daytime sleepiness, disturbed sleep, and snoring. The aim of this study was to characterize sleep in children with SRS and to evaluate the impact of recombinant growth hormone (rGH) therapy. MethodsWe performed a retrospective analysis of sleep recordings in 40 patients with molecularly proven SRS (methylation anomaly in 11p15 [n = 32] or maternal uniparental disomy of chromosome 7 [n = 16]). Sleep recordings were either by means of polygraphy or polysomnography (PSG) (n = 16). A total of 34 patients received rGH therapy. ResultsWe collected 61 sleep recordings. The mean apnea−hypopnea index (AHI) was 3.4 events/h (0–12.4), with a mean central AHI of 0.5 events/h (0–2.4). SDB was identified in 73.8% (n = 45) of the recordings and was severe in 4.9%. SDB was present in 86.4% of patients before rGH therapy and was severe in 13.6%. AHI worsened for 5 of 12 patients with sleep recordings before and after rGH therapy initiation, reaching mild impairment. The mean rGH dose was 32.3 μg/kg/(12.9–51.4), with a mean insulin-like growth factor 1 plasma level of 1.7 SDS (−1.9 to 6.6). ConclusionMost patients with SRS present with SDB with an obstructive profile, possibly explained by narrowing of the airways and lymphoid organ hypertrophy. We recommend systematic ear−nose−throat evaluation of SRS patients and PSG if there are clinical anomalies, preferably before initiating rGH therapy, to monitor and adapt the management of patients with SDB.

Association of four imprinting disorders and ART

BackgroundHuman-assisted reproductive technologies (ART) are a widely accepted treatment for infertile couples. At the same time, many studies have suggested the correlation between ART and increased incidences of normally rare imprinting disorders such as Beckwith-Wiedemann syndrome (BWS), Angelman syndrome (AS), Prader-Willi syndrome (PWS), and Silver-Russell syndrome (SRS). Major methylation dynamics take place during cell development and the preimplantation stages of embryonic development. ART may prevent the proper erasure, establishment, and maintenance of DNA methylation. However, the causes and ART risk factors for these disorders are not well understood.ResultsA nationwide epidemiological study in Japan in 2015 in which 2777 pediatrics departments were contacted and a total of 931 patients with imprinting disorders including 117 BWS, 227 AS, 520 PWS, and 67 SRS patients, were recruited. We found 4.46- and 8.91-fold increased frequencies of BWS and SRS associated with ART, respectively. Most of these patients were conceived via in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), and showed aberrant imprinted DNA methylation. We also found that ART-conceived SRS (ART-SRS) patients had incomplete and more widespread DNA methylation variations than spontaneously conceived SRS patients, especially in sperm-specific methylated regions using reduced representation bisulfite sequencing to compare DNA methylomes. In addition, we found that the ART patients with one of three imprinting disorders, PWS, AS, and SRS, displayed additional minor phenotypes and lack of the phenotypes. The frequency of ART-conceived Prader-Willi syndrome (ART-PWS) was 3.44-fold higher than anticipated. When maternal age was 37 years or less, the rate of DNA methylation errors in ART-PWS patients was significantly increased compared with spontaneously conceived PWS patients.ConclusionsWe reconfirmed the association between ART and imprinting disorders. In addition, we found unique methylation patterns in ART-SRS patients, therefore, concluded that the imprinting disorders related to ART might tend to take place just after fertilization at a time when the epigenome is most vulnerable and might be affected by the techniques of manipulation used for IVF or ICSI and the culture medium of the fertilized egg.

Gonadal function and pubertal development in patients with Silver-Russell syndrome.

Is gonadal function affected in males and females with Silver-Russell Syndrome (SRS)? Sertoli cell dysfunction is more common in males with SRS, with 11p15 LOM, but gonadal function seems to be unaffected in females with SRS. Males with SRS have an increased risk for genital abnormalities such as cryptorchidism and hypospadias, which could be associated with reproductive problems in later life. In SRS females, an association has been described with Mayer-Rokitansky-Küster-Hauser syndrome, which might compromise their reproductive function. Longitudinal follow-up study, involving 154 subjects, over a time period of 20 years. Thirty-one SRS patients (14 males) and 123 non-SRS patients born at same gestational age (SGA; 65 males). All received growth hormone and 27.3% received additional gonadotropin-releasing hormone analog treatment (GnRHa). Mean age at onset of puberty was 11.5 years in SRS males versus 11.6 years in non-SRS males (P = 0.51), and 10.5 years in SRS females versus 10.7 years in non-SRS females (P = 0.50). Four of the 14 SRS males had a post-pubertal inhibin-B level below the fifth percentile compared to healthy controls, and two of them an FSH above the 95th percentile, indicating Sertoli cell dysfunction. One of them had a history of bilateral cryptorchidism and orchiopexy. All SRS females had AMH, LH and FSH levels within the reference range. Pubertal duration to Tanner stage five was similar in SRS and non-SRS. Pubertal height gain was better in SRS patients who additionally received GnRHa (P < 0.01). Mean age at menarche was 13.1 years in SRS versus 13.3 years in non-SRS (P = 0.62). One SRS female had primary amenorrhea due to Müllerian agenesis. As this is a rare syndrome, the SRS group had a small size. As gonadal function is not affected in females with SRS, it is likely that reproductive function is also not affected. Sertoli cell dysfunction in males with SRS could cause impaired reproductive function and should be assessed during pubertal development. No external funding was used for the study. The authors have no conflicts of interest.

Hypomethylation of HOXA4 promoter is common in Silver-Russell syndrome and growth restriction and associates with stature in healthy children

Silver-Russell syndrome (SRS) is a growth retardation syndrome in which loss of methylation on chromosome 11p15 (11p15 LOM) and maternal uniparental disomy for chromosome 7 [UPD(7)mat] explain 20–60% and 10% of the syndrome, respectively. To search for a molecular cause for the remaining SRS cases, and to find a possible common epigenetic change, we studied DNA methylation pattern of more than 450 000 CpG sites in 44 SRS patients. Common to all three SRS subgroups, we found a hypomethylated region at the promoter region of HOXA4 in 55% of the patients. We then tested 39 patients with severe growth restriction of unknown etiology, and found hypomethylation of HOXA4 in 44% of the patients. Finally, we found that methylation at multiple CpG sites in the HOXA4 promoter region was associated with height in a cohort of 227 healthy children, suggesting that HOXA4 may play a role in regulating human growth by epigenetic mechanisms.

Genetic disruption of the oncogenic HMGA2\u2013PLAG1\u2013IGF2 pathway causes fetal growth restriction

PurposeFetal growth is a complex process involving maternal, placental and fetal factors. The etiology of fetal growth retardation remains unknown in many cases. The aim of this study is to identify novel human mutations and genes related to Silver–Russell syndrome (SRS), a syndromic form of fetal growth retardation, usually caused by epigenetic downregulation of the potent fetal growth factor IGF2.MethodsWhole-exome sequencing was carried out on members of an SRS familial case. The candidate gene from the familial case and two other genes were screened by targeted high-throughput sequencing in a large cohort of suspected SRS patients. Functional experiments were then used to link these genes into a regulatory pathway.ResultsWe report the first mutations of the PLAG1 gene in humans, as well as new mutations in HMGA2 and IGF2 in six sporadic and/or familial cases of SRS. We demonstrate that HMGA2 regulates IGF2 expression through PLAG1 and in a PLAG1-independent manner.ConclusionGenetic defects of the HMGA2–PLAG1–IGF2 pathway can lead to fetal and postnatal growth restriction, highlighting the role of this oncogenic pathway in the fine regulation of physiological fetal/postnatal growth. This work defines new genetic causes of SRS, important for genetic counseling.

The Diagnostic Value of IGF-2 and the IGF/IGFBP-3 System in Silver-Russell Syndrome

Background/Aims: Recently, we have described a family of 4 members presenting with intrauterine and postnatal growth failure, low IGF-2 levels, and signs of Silver-Russell syndrome (SRS) who carried a genomic IGF2 mutation. Here, we assess the value of IGF-2 in relation to SRS. Methods: We collected data from 48 SRS children and 48 short children born small for gestational age (SGA) seen at our center. The SRS children were 4.6 ± 2.0 years of age, and the SGA children were 4.8 ± 1.8 years of age. All patients were prepubertal and growth hormone naive. An 11p15 ICR1 loss of methylation (11p15LOM) was present in 22, maternal uniparental disomy of chromosome 7 (upd(7)mat) in 7, and IGF2 genomic mutation (IGF2mut) in 3 patients. Growth factors were measured by in-house radioimmunoassays. Results: The median IGF-2 standard deviation scores (SDSs) were: IGF2mut –1.75, upd(7)mat –1.69, nonsyndromic SGA –1.52, 11p15LOM –0.61, and clinical (tested negative) –0.55. The median IGF-2:IGF-1 concentration ratio was 2.57 in IGF2mut compared to 5.44 in 11p15LOM (p = 0.036), 7.84 in clinical, and 7.98 in upd(7)mat. Upd(7)mat patients had significantly lower IGF-1 and IGFBP-3 SDSs than patients with 11p15LOM (p ≤ 0.002). Conclusion: Serum IGF-2 in combination with IGF-1 and IGFBP-3 can add to the clinical signs of SRS patients and help to perform targeted genetic testing. Further studies are needed.