Effect of Cyproheptadine on Weight and Growth Velocity in Children With Silver-Russell Syndrome

Clinical characterization of PLAG1- related Silver-Russell syndrome：A clinical report

BACKGROUND

Silver-Russell syndrome (SRS) is a rare genetic disorder that is mainly associated with prenatal and postnatal growth retardation. Loss of methylation on chromosome 11p15 and maternal uniparental disomy on chromosome 7 (upd(7)mat) are two common causes, accounting for approximately 50% and 10% of all patients, respectively. Pathogenic variants of genes, such as HMGA2, IGF2, CDKN1C, and PLAG1, have also been detected in patients with SRS. So far, SRS caused by PLAG1 alterations have only been described in two sporadic cases and three families.

PATIENT PRESENTATION

The genetic and clinical manifestations of SRS in a patient carrying a novel variant of PLAG1 were reported and these results were compared with those of five previously reported cases. Trio-based whole-exome sequencing revealed a heterozygous variation in PLAG1 (NM_002655.3: c.131del; p.(Asn44Thrfs*6)) in an infant girl with clinical suspicion of SRS. Familial studies confirmed that the mutation was inherited from her father. As seen in previously reported cases, the patient presented with prenatal and postnatal growth retardation, relative macrocephaly at birth, prominent forehead during infancy, and triangular face. However, no clinical characteristics such as feeding difficulties, hypothyroidism, or psychomotor and speech delay.

CONCLUSIONS

This study identified the sixth documented case of PLAG1 variants leading to SRS and expanded our knowledge of the molecular spectrum of SRS phenotypes.

Imprinting disorders

Imprinting disorders (ImpDis) are congenital conditions that are characterized by disturbances of genomic imprinting. The most common individual ImpDis are Prader-Willi syndrome, Angelman syndrome and Beckwith-Wiedemann syndrome. Individual ImpDis have similar clinical features, such as growth disturbances and developmental delay, but the disorders are heterogeneous and the key clinical manifestations are often non-specific, rendering diagnosis difficult. Four types of genomic and imprinting defect (ImpDef) affecting differentially methylated regions (DMRs) can cause ImpDis. These defects affect the monoallelic and parent-of-origin-specific expression of imprinted genes. The regulation within DMRs as well as their functional consequences are mainly unknown, but functional cross-talk between imprinted genes and functional pathways has been identified, giving insight into the pathophysiology of ImpDefs. Treatment of ImpDis is symptomatic. Targeted therapies are lacking owing to the rarity of these disorders; however, personalized treatments are in development. Understanding the underlying mechanisms of ImpDis, and improving diagnosis and treatment of these disorders, requires a multidisciplinary approach with input from patient representatives.

Promising therapeutic aspects in human genetic imprinting disorders

Genomic imprinting is an epigenetic phenomenon of monoallelic gene expression pattern depending on parental origin. In humans, congenital imprinting disruptions resulting from genetic or epigenetic mechanisms can cause a group of diseases known as genetic imprinting disorders (IDs). Genetic IDs involve several distinct syndromes sharing homologies in terms of genetic etiologies and phenotypic features. However, the molecular pathogenesis of genetic IDs is complex and remains largely uncharacterized, resulting in a lack of effective therapeutic approaches for patients. In this review, we begin with an overview of the genomic and epigenomic molecular basis of human genetic IDs. Notably, we address ethical aspects as a priority of employing emerging techniques for therapeutic applications in human IDs. With a particular focus, we delineate the current field of emerging therapeutics for genetic IDs. We briefly summarize novel symptomatic drugs and highlight the key milestones of new techniques and therapeutic programs as they stand today which can offer highly promising disease-modifying interventions for genetic IDs accompanied by various challenges.

Height and body mass index in molecularly confirmed Silver-Russell syndrome and the long-term effects of growth hormone treatment

OBJECTIVE

Silver-Russell syndrome (SRS) causes short stature. Growth hormone (GH) treatment aims to increase adult height. However, data are limited on the long-term outcomes of GH in patients with molecularly confirmed SRS. This study evaluated height, body mass index (BMI) and GH treatment in molecularly confirmed SRS.

DESIGN

An observational study with retrospective data collection.

PATIENTS

Individuals with molecularly confirmed SRS aged ≥13 years.

MEASUREMENTS

Data were collected on height, height gain (change in height standard deviation score [SDS] from childhood to final or near-final height), BMI and gain in BMI (from childhood to adulthood) and previous GH treatment.

RESULTS

Seventy-one individuals (40 female) were included. The median age was 22.0 years (range 13.2-69.7). The molecular diagnoses: H19/IGF2:IG-DMR LOM in 80.3% (57/71); upd(7)mat in 16.9% (12/71) and IGF2 mutation in 2.8% (2/71). GH treatment occurred in 77.5% (55/71). Total height gain was greater in GH-treated individuals (median 1.53 SDS vs. 0.53 SDS, p = .007), who were shorter at treatment initiation (-3.46 SDS vs. -2.91 SDS, p = .04) but reached comparable heights to GH-untreated individuals (-2.22 SDS vs. -2.74 SDS, p = .7). In GH-treated individuals, BMI SDS was lower at the most recent assessment (median -1.10 vs. 1.66, p = .002) with lower BMI gain (2.01 vs. 3.58, p = .006) despite similar early BMI SDS to GH-untreated individuals (median -2.65 vs. -2.78, p = .3).

CONCLUSIONS

These results support the use of GH in SRS for increasing height SDS. GH treatment was associated with lower adult BMI which may reflect improved metabolic health even following discontinuation of therapy.

Safety of Cyproheptadine, an Orexigenic Drug. Analysis of the French National Pharmacovigilance Data-Base and Systematic Review

Objectives: Cyproheptadine is a first-generation H1-antihistamine drug first that was distributed in the 1960s. While its orexigenic effect was observed early, cyproheptadine is not yet authorized for this indication in all countries today. There is an increasing medical interest and demand for the orexigenic effect of cyproheptadine, especially in children with poor appetite. As cyproheptadine might be evaluated in future clinical trials, we wanted to assess its safety profile. Methods: Using the French national pharmacovigilance database, we retrospectively analyzed all pediatric and adult reports of adverse effects of cyproheptadine recorded since its first distribution in France. Next, we performed a systematic review of the literature of cyproheptadine adverse effects. Results: Since 1985, 93 adverse effects were reported in the French pharmacovigilance database (adults 81.7%, children 18.3%); these were mainly neurological symptoms (n = 38, adults 71%, children 28.9%), and hepatic complications (n = 15, adults 86.7%, children 13.3%). In the literature, the most frequent adverse effect reported was drowsiness in adults or children, and five case reports noted liver complications in adults. We estimated the frequency of hepatic adverse effects at 0.27 to 1.4/1000, regardless of age. Conclusion: Cyproheptadine can be considered a safe drug. Mild neurological effects appear to be frequent, and hepatotoxicity is uncommon to rare. Randomized controlled trials are needed to evaluate the safety and efficacy of cyproheptadine before authorization for appetite stimulation, especially in young children as studies at this age are lacking. Possible hepatic complications should be monitored, as very rare cases of liver failure have been reported.

A novel treatment for height growth in patients with growth hormone insensitivity syndrome by cyproheptadine hydrochloride

BACKGROUND

Cyproheptadine HCl (CyproH) is an appetite-stimulating drug and while it was prescribed for a patient with growth hormone insensitivity syndrome (GHIS) for increasing appetite, his height growth was surprisingly increased. Therefore, the aim of this study was to investigate the effect of CyproH on growth parameters of the patients with GHIS.

PATIENTS AND DESIGN

Twenty patients were enrolled in two prospective cohorts at two different times. Fifteen cases were observed for 1.17 ± 1.3 years without treatment (observation period, OP). Then, CyproH was administered for 2.2 ± 2.7 years (treatment period, TP), and growth parameters were compared within these two periods. Five patients who did not receive any treatment for 1-8.24 years (4 ± 2.9) were the control group.

RESULTS

Height velocity (HV) increased from 1.88 ± 0.7 to 6.1 ± 0.8 cm/year and HV-SDS reached from -4.5 ± 0.74 to -0.21 ± 1.2 in OP and TP, respectively (P < .001), whereas HV and HV-SDS were 2.2 ± 1.1 cm/yr and -4.2 ± 1.2, respectively, in controls (P < .001). Height SDS was -7.0 ± 1.7 and increased to -6 ± 2.2 after treatment (P = .002). Gain in height was 2.3 ± 0.6 SDS in 5 patients who were treated for 5.4 ± 2.8 years. BMI-SDS was not significantly changed within two time periods and also in cases and controls.

CONCLUSION

CyproH caused height growth in the patients with GHIS, and therefore, this treatment can be considered as an alternative option to IGF-I injection.