The SHORT syndrome: further delineation and natural history

SHORT Syndrome: Systematic Appraisal of the Medical and Dental Phenotype

INTRODUCTION

SHORT syndrome is a rare autosomal dominant condition described by its acronym of short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger abnormality, and teething delay. Individuals have a distinct progeroid craniofacial appearance with a triangular face, frontal bossing, hypoplastic or thin alae nasi, large low-set ears, and mandibular retrognathia.

OBJECTIVES

To systematically appraise the literature and update the clinical phenotype with emphasis on the dental condition.

DESIGN

A systematic literature search was carried out to update the clinical phenotype, identifying reports of individuals with SHORT syndrome published after August 2015. The same search strategy but not limited to publication date was carried out to identify reports of the dental phenotype. Two independent reviewers screened 1937 articles with 55 articles identified for full-text review.

RESULTS

Nineteen individuals from 11 families were identified. Facial dysmorphism including ocular depression, triangular shaped face, frontal bossing, large low-set ears, and micrognathia were the most consistent features followed by lipodystrophy, insulin resistance, and intrauterine growth restriction. Teething delay, microdontia, hypodontia, and enamel hypoplasia have all been reported.

CONCLUSION

Features that comprise the SHORT acronym do not accurately or completely describe the clinical phenotype. The craniofacial appearance is one of the most consistent features. Lipodystrophy and insulin resistance may also be considered cardinal features. After teething delay, enamel hypoplasia and microdontia are the most common dental manifestations. We present recommendations for the dental and orthodontic/orthognathic management of individuals with SHORT syndrome.

The first SHORT syndrome in a Taiwanese boy: A case report and review of the literature

SHORT syndrome is a rare, multisystem disease named with the acronym arising from short stature, hyperextensibility of joints, ocular depression, Rieger anomaly, and teething delay. Metabolic anomalies such as insulin resistance and diabetes are also present. This disease is related to heterozygous variants in the PIK3R1 and is inherited in an autosomal-dominant manner. In this case report, we present a Taiwanese boy with SHORT syndrome who had growth retardation and dysmorphic features, including a triangular face, prominent forehead, and small chin. We performed anthropometric and laboratory measurements and imaging examinations. We noted no insulin resistance or diabetes. We performed whole exome and Sanger sequencing and confirmed the underlying genetic variant, detecting a heterozygous variant of PIK3R1 (NM_181523.3) (c.1945C > T). In a family survey, his parents indicated no similar clinical symptoms and no gene variant. This case is the first SHORT syndrome in Taiwan. Specific facial dysmorphisms of this case help us confirm the diagnosis with timely genetic testing and then we can provide appropriate management and proper care.

A novel PIK3R1 mutation of SHORT syndrome in a Chinese female with diffuse thyroid disease: a case report and review of literature

Background

SHORT syndrome is a rare genetic disease named with the acronyms of short stature, hyper-extensibility of joints, ocular depression, Rieger anomaly and teething delay. It is inherited in an autosomal dominant manner confirmed by the identification of heterozygous mutations in PIK3R1. This study hereby presents a 15-year-old female with intrauterine growth restriction, short stature, teething delay, characteristic facial gestalts who was identified a novel de novo nonsense mutation in PIK3R1.

Case presentation

The proband was admitted to our department due to irregular menstrual cycle and hirsutism with short stature, who had a history of intrauterine growth restriction and presented with short stature, teething delay, characteristic facial gestalts, hirsutism, and thyroid disease. Whole-exome sequencing and Sanger sequencing revealed c.1960C > T, a novel de novo nonsense mutation, leading to the termination of protein translation (p. Gln654*).

Conclusions

This is the first case report of SHORT syndrome complicated with thyroid disease in China, identifying a novel de novo heterozygous nonsense mutation in PIK3R1 gene (p. Gln654*). The phenotypes are mildly different from other cases previously described in the literature, in which our patient presents with lipoatrophy, facial feature, and first reported thyroid disease. Thyroid disease may be a new clinical symptom of patients with SHORT syndrome.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12881-020-01146-3.

Inhibition of the PI 3-kinase pathway disrupts the unfolded protein response and reduces sensitivity to ER stress-dependent apoptosis

Class Ia phosphoinositide 3-kinases (PI3K) are critical mediators of insulin and growth factor action. We have demonstrated that the p85α regulatory subunit of PI3K modulates the unfolded protein response (UPR) by interacting with and regulating the nuclear translocation of XBP-1s, a transcription factor essential for the UPR. We now show that PI3K activity is required for full activation of the UPR. Pharmacological inhibition of PI3K in cells blunts the ER stress-dependent phosphorylation of IRE1α and PERK, decreases induction of ATF4, CHOP, and XBP-1 and upregulates UPR target genes. Cells expressing a human p85α mutant (R649W) previously shown to inhibit PI3K, exhibit decreased activation of IRE1α and PERK and reduced induction of CHOP and ATF4. Pharmacological inhibition of PI3K, overexpression of a mutant of p85α that lacks the ability to interact with the p110α catalytic subunit (∆p85α) or expression of mutant p85α (R649W) in vivo, decreased UPR-dependent induction of ER stress response genes. Acute tunicamycin treatment of R649W^+/- mice revealed reduced induction of UPR target genes in adipose tissue, whereas chronic tunicamycin exposure caused sustained increases in UPR target genes in adipose tissue. Finally, R649W^+/- cells exhibited a dramatic resistance to ER stress-dependent apoptosis. These data suggest that PI3K pathway dysfunction causes ER stress that may drive the pathogenesis of several diseases including Type 2 diabetes and various cancers.

SHORT syndrome in two Chinese girls: A case report and review of the literature

Background

SHORT syndrome is a rare inherited multisystem disease that includes characteristic facial features, growth retardation, and metabolic anomalies and is related to heterozygous mutations in the PIK3R1 gene. However, it is difficult to ascertain the relationship between the phenotype and the genotype quickly and efficiently.

Methods

We report two Chinese girls with SHORT syndrome who presented with growth retardation, dysmorphic features, insulin resistance, and diabetes. Comprehensive medical evaluations were collected, including anthropometric measurements, laboratory measurements, and imaging examinations. Whole exome and Sanger sequencing was performed to detect and confirm the underlying genetic mutations in these patients. We prescribed metformin for the patients.

Results

The patients both presented diabetes, insulin resistance, short stature, lipodystrophy, and characteristic facial dysmorphic features. A heterozygous mutation was detected in the PIK3R1 gene (c.1615_1617del) of Patient 1. The analysis of patient 2 revealed another PIK3R1 mutation (c.1945C>T). After family validation, neither their parents nor their brothers had similar clinical presentations or carried the same mutation.

Conclusion

We identified two de novo heterozygous mutations in PIK3R1 as the cause of SHORT syndrome in two Chinese girls. Additionally, in terms of diabetes control, metformin works well in the early treatment stage.

Transgenic Mice Overexpressing SREBP-1a in Male ob/ob Mice Exhibit Lipodystrophy and Exacerbate Insulin Resistance

Sterol regulatory element-binding protein (SREBP)-1a is a key transcription factor that activates the expression of genes involved in the synthesis of fatty acids, triglycerides (TGs), and cholesterol. Transgenic mice that overexpress the nuclear form of SREBP-1a under the control of the phosphoenolpyruvate carboxykinase promoter (Tg-1a) were previously shown to display a lipodystrophic phenotype characterized by enlarged and fatty livers, diminished peripheral white adipose tissue (WAT), and insulin resistance. In the current study, we crossed these Tg-1a mice with genetically obese (ob/ob) mice (Tg-1a;ob/ob) and examined change in fat distribution between liver and adipose tissues in severe obesity and mechanism underlying the lipodystrophic phenotype in mice with Tg-1a. Tg-1a;ob/ob mice developed more severe steatohepatitis but had reduced WAT mass and body weight compared with ob/ob mice. The reduction of WAT mass in Tg-1a and Tg-1a;ob/ob mice was accompanied by enhanced lipogenesis and lipid uptake in the liver, reduced plasma lipid levels, impaired adipocyte differentiation, reduced food intake, enhanced energy expenditure, and extended macrophage infiltration and fibrosis in WAT. Despite the improved glucose tolerance, Tg-1a;ob/ob mice showed severe peripheral insulin resistance. Adenoviral hepatic expression of SREBP-1a mimicked these phenotypes. The "fat steal"-like lipodystrophy phenotype of the Tg-1a;ob/ob model demonstrates that hepatic SREBP-1a activation has a strong impact on the partition of TG accumulation, resulting in adipose-tissue remodeling by inflammation and fibrosis and insulin resistance.

SHORT syndrome in a two-year-old girl - case report

Background

SHORT syndrome is a rare genetic congenital defects condition. The frequency of the disease still remains unknown.

Case presentation

We report the two-year-four-month old female with SHORT syndrome who present growth retardation and dysmorphic features (triangular-shaped face, prominent forehead, ocular depression, lipodystrophy at the lumbar region and around elbows), consistent with the phenotype described for this syndrome.

The molecular analysis showed the presence of heterozygous variant c.1956dupT (p.Lys653*) in exon 15 of PIK3R1.

Conclusions

The frequency of the disease still remains unknown; solely several dozen cases have been described worldwide.

PI3-kinase mutation linked to insulin and growth factor resistance in vivo

The phosphatidylinositol 3-kinase (PI3K) signaling pathway is central to the action of insulin and many growth factors. Heterozygous mutations in the gene encoding the p85α regulatory subunit of PI3K (PIK3R1) have been identified in patients with SHORT syndrome - a disorder characterized by short stature, partial lipodystrophy, and insulin resistance. Here, we evaluated whether SHORT syndrome-associated PIK3R1 mutations account for the pathophysiology that underlies the abnormalities by generating knockin mice that are heterozygous for the Pik3r1Arg649Trp mutation, which is homologous to the mutation found in the majority of affected individuals. Similar to the patients, mutant mice exhibited a reduction in body weight and length, partial lipodystrophy, and systemic insulin resistance. These derangements were associated with a reduced capacity of insulin and other growth factors to activate PI3K in liver, muscle, and fat; marked insulin resistance in liver and fat of mutation-harboring animals; and insulin resistance in vitro in cells derived from these mice. In addition, mutant mice displayed defective insulin secretion and GLP-1 action on islets in vivo and in vitro. These data demonstrate the ability of this heterozygous mutation to alter PI3K activity in vivo and the central role of PI3K in insulin/growth factor action, adipocyte function, and glucose metabolism.

Primordial dwarfism: an update

PURPOSE OF REVIEW

To review the recent advances in the clinical and molecular characterization of primordial dwarfism, an extreme growth deficiency disorder that has its onset during embryonic development and persists throughout life.

RECENT FINDINGS

The last decade has witnessed an unprecedented acceleration in the discovery of genes mutated in primordial dwarfism, from one gene to more than a dozen genes. These genetic discoveries have confirmed the notion that primordial dwarfism is caused by defects in basic cellular processes, most notably centriolar biology and DNA damage response. Fortunately, the increasing number of reported clinical primordial dwarfism subtypes has been accompanied by more accurate molecular classification.

SUMMARY

Qualitative defects of centrioles with resulting abnormal mitosis dynamics, reduced proliferation, and increased apoptosis represent the predominant molecular pathogenic mechanism in primordial dwarfism. Impaired DNA damage response is another important mechanism, which we now know is not mutually exclusive to abnormal centrioles. Molecular characterization of primordial dwarfism is helping families by enabling more reproductive choices and may pave the way for the future development of therapeutics.

PIK3R1 mutations in SHORT syndrome

SHORT syndrome (OMIM 269880) is a rare autosomal-dominant disorder characterized by short stature, hyperextensibility of joints, hernias, ocular depression, ophthalmic anomalies (Rieger anomaly, posterior embryotoxon, glaucoma), teething delay, partial lipodystrophy, insulin resistance and facial dysmorphic signs. Heterozygous mutations in PIK3R1 were recently identified in 14 families with SHORT syndrome. Eight of these families had a recurrent missense mutation (c.1945C>T; p.Arg649Trp). We report on two unrelated patients with typical clinical features of SHORT syndrome and additional problems such as pulmonary stenosis and ectopic kidney. Analysis of PIK3R1 revealed the mutation c.1945C>T; p.Arg649Trp de novo in both patients. These two patients not only provide additional evidence that PIK3R1 mutations cause SHORT syndrome, but also broaden the clinical spectrum of this syndrome and further confirm that the amino acid exchange c.1945C>T; p.Arg649Trp is a hotspot mutation in this gene.

Autosomal dominant PIK3R1 mutations cause SHORT syndrome

PIK3R1 mutations cause syndromic insulin resistance with lipoatrophy. Thauvin-Robinet et al. (2013) The American Journal of Human Genetics 93: 141-149 SHORT syndrome with partial lipodystrophy due to impaired phosphatidylinositol 3 kinase signalling. Chudasama et al. (2013) The American Journal of Human Genetics 93: 150-157 Mutations in PIK3R1 cause SHORT syndrome. Dyment et al. (2013) The American Journal of Human Genetics 93: 158-166.

Mutations in PIK3R1 cause SHORT syndrome

SHORT syndrome is a rare, multisystem disease characterized by short stature, anterior-chamber eye anomalies, characteristic facial features, lipodystrophy, hernias, hyperextensibility, and delayed dentition. As part of the FORGE (Finding of Rare Disease Genes) Canada Consortium, we studied individuals with clinical features of SHORT syndrome to identify the genetic etiology of this rare disease. Whole-exome sequencing in a family trio of an affected child and unaffected parents identified a de novo frameshift insertion, c.1906_1907insC (p.Asn636Thrfs*18), in exon 14 of PIK3R1. Heterozygous mutations in exon 14 of PIK3R1 were subsequently identified by Sanger sequencing in three additional affected individuals and two affected family members. One of these mutations, c.1945C>T (p.Arg649Trp), was confirmed to be a de novo mutation in one affected individual and was also identified and shown to segregate with the phenotype in an unrelated family. The other mutation, a de novo truncating mutation (c.1971T>G [p.Tyr657*]), was identified in another affected individual. PIK3R1 is involved in the phosphatidylinositol 3 kinase (PI3K) signaling cascade and, as such, plays an important role in cell growth, proliferation, and survival. Functional studies on lymphoblastoid cells with the PIK3R1 c.1906_1907insC mutation showed decreased phosphorylation of the downstream S6 target of the PI3K-AKT-mTOR pathway. Our findings show that PIK3R1 mutations are the major cause of SHORT syndrome and suggest that the molecular mechanism of disease might involve downregulation of the PI3K-AKT-mTOR pathway.

Review and hypothesis: syndromes with severe intrauterine growth restriction and very short stature--are they related to the epigenetic mechanism(s) of fetal survival involved in the developmental origins of adult health and disease?

Diagnosing the specific type of severe intrauterine growth restriction (IUGR) that also has post-birth growth restriction is often difficult. Eight relatively common syndromes are discussed identifying their unique distinguishing features, overlapping features, and those features common to all eight syndromes. Many of these signs take a few years to develop and the lifetime natural history of the disorders has not yet been completely clarified. The theory behind developmental origins of adult health and disease suggests that there are mammalian epigenetic fetal survival mechanisms that downregulate fetal growth, both in order for the fetus to survive until birth and to prepare it for a restricted extra-uterine environment, and that these mechanisms have long lasting effects on the adult health of the individual. Silver-Russell syndrome phenotype has recently been recognized to be related to imprinting/methylation defects. Perhaps all eight syndromes, including those with single gene mutation origin, involve the mammalian mechanism(s) of fetal survival downsizing. Insights into those mechanisms should provide avenues to understanding the natural history, the heterogeneity and possible therapy not only for these eight syndromes, but for the common adult diseases with which IUGR is associated.

Lipodystrophies: disorders of adipose tissue biology

The adipocytes synthesize and store triglycerides as lipid droplets surrounded by various proteins and phospholipids at its surface. Recently, the molecular basis of some of the genetic syndromes of lipodystrophies has been elucidated and some of these genetic loci have been found to contribute to lipid droplet formation in adipocytes. The two main types of genetic lipodystrophies are congenital generalized lipodystrophy (CGL) and familial partial lipodystrophy (FPL). So far, three CGL loci: 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), Berardinelli-Seip Congenital Lipodystrophy 2 (BSCL2) and caveolin 1 (CAV1) and four FPL loci: lamin A/C (LMNA), peroxisome proliferator-activated receptor gamma (PPARG), v-AKT murine thymoma oncogene homolog 2 (AKT2) and zinc metalloprotease (ZMPSTE24), have been identified. AGPAT2 plays a critical role in the synthesis of glycerophospholipids and triglycerides required for lipid droplet formation. Another protein, seipin (encoded by BSCL2 gene), has been found to induce lipid droplet fusion. CAV1 is an integral component of caveolae and might contribute towards lipid droplet formation. PPARgamma and AKT2 play important role in adipogenesis and lipid synthesis. In this review, we discuss and speculate about the contribution of various lipodystrophy genes and their products in the lipid droplet formation.

Cataracte congénitale

Cataract is a loss of lens transparency because of a protein alteration. Etiopathogenesis is poorly understood but new mutations of different developmental genes involved are found in 25% of cases. Frequency of onset, particularly when different ocular development anomalies occur, is related to the lens induction phenomena on the eye's anterior segment structure during embryologic development. Genetic transmission is often found on the dominant autosomal mode. Diagnosis is based on a complete and detailed examination of the eye, often with general anaesthesia. This condition predisposes children to later, sometimes serious amblyopia. Different clinical aspects can be observed: from cataract with ocular and/or systemic anomalies to polymalformative syndrome, skeletal, dermatological, neurological, metabolic, and genetic or chromosomal diseases. A general systematic pediatric examination is necessary. Congenital cataract requires first and foremost early diagnosis and a search for all etiologies. Surgical treatment is adapted case by case but it has progressed with the quality of today's intraocular lenses even if systematic implantation continues to be debated. Life-long monitoring is absolutely necessary.

Is SHORT syndrome another phenotypic variation of PITX2?

Even though responsible genetic loci and mode of inheritance for the Rieger syndrome have been well established, the mode of inheritance and the genetic basis for SHORT syndrome are still uncertain. The purpose of this paper is to document a familial translocation of t(1;4)(q31.2;q25), in a mother and her son manifesting Rieger syndrome with polycystic ovaries and SHORT syndrome, respectively. It is suggested that these two syndromes may be different expressions of the same gene, PITX2, localized at 4q25. Our patient is the second with the association of Rieger syndrome and polycystic ovaries, and thus this may not be coincidental, moreover insulin resistance-related phenotypes, such as lipodystrophy and polycystic ovaries, can be major component of syndromes with Rieger eye malformation.

Congenital generalized lipodystrophy, mental retardation, deafness, short stature, and slender bones: a newly recognized syndrome?

We present three patients with congenital generalized lipodystrophy, sensorineural deafness, low birth weight, short stature, delayed cognitive development, and progressive bone changes characterized by overtubulation and rarefaction of long bones with dense metaphyseal striations occurring in adolescence. Abnormalities of lipid and carbohydrate metabolism, hepatosplenomegaly, acanthosis nigricans, and hirsutism were not found. Comparison of the condition of these patients with known syndromic lipodystrophies suggests that they represent a previously unrecognized genetic disorder. The occurrence in sibs born to consanguineous parents and a third patient from the same tribal unit suggest autosomal recessive inheritance.

SHORT syndrome

We describe a mother and her son with short stature, progeroid facies, Rieger anomaly, teething delay, and mild developmental retardation, particularly speech delay, which are characteristic features of the SHORT syndrome. An additional sign of all described patients is the slight build with lack of subcutaneous fat. Resistance to insulin was suggested by an oral glucose tolerance test in the mother, whereas the test was normal in the index patient at the age of 2 years 2 months. We review the literature and discuss the name-giving symptoms critically. Five familial cases in different generations, equally affected male and female patients and male-to-male transmission point to an autosomal dominant mode of inheritance.

Barraquer-Simons syndrome (with sensorineural deafness): a contribution to the differential diagnosis of lipodystrophy syndromes

Among the lipodystrophies, the Barraquer-Simons syndrome is a rare condition. We describe a 27-year-old woman with progressive loss of subcutaneous fat after 15 years first affecting the face and spreading to the upper part of the body. She also suffered from deafness and had marked changes in cranial MRI. We discuss possible differential diagnosis such as the Cockayne, SHORT and Berardinelli-Seip syndrome.

SHORT syndrome: a new case with probable autosomal dominant inheritance

A further case of SHORT syndrome is reported. This 9-year-old Italian boy was short of stature and had partial lipodystrophy, minor facial anomalies, mild hyperextensibility of joints, ocular depression, Rieger anomaly, delay in speech development and in dental eruption. The father and sister showed a striking similarity to the propositus. Moreover, the sister had bilateral and symmetrical lens opacities, which have not been reported previously in affected subjects or their relatives. A variable expression of an autosomal dominant gene can be considered in the present family.

Absent iris stroma, narrow body build and small facial bones: a new association or variant of SHORT syndrome?

We report four patients from two unrelated families with strikingly similar facial appearance, short stature, narrow body build and, in two of the patients, abnormalities of the iris stroma. The birth of an affected offspring suggests that this syndrome is likely to have autosomal dominant inheritance. The facial appearance and some of the features resemble the SHORT syndrome, the name being an acronym for Short stature, Hyperextensible joints, Ocular depression, Rieger anomaly and abnormalities of the Teeth. The relationship of the syndrome to the SHORT syndrome is discussed.

Adverse events during growth hormone therapy

The aim of this study was to ascertain the frequency of adverse events occuring during GH therapy in Australia and New Zealand since 1988. Data for children receiving GH has been collected prospectively on a national database, OZGROW, after informed consent has been given. Adverse events were coded by clinicians and have been analysed in relation to the nature of the event and the underlying diagnosis. There were 2922 subjects analysed, representing 9004 years of GH therapy. 151 subjects reported a total of 210 adverse events giving an overall frequency of 2.3% adverse events/patient treated year. Events that were probably related to GH therapy included peripheral oedema, injection site problems and increased frequency of kyphoscoliosis and slipped epiphysis in some groups. Adverse events were more frequent in growth hormone deficient children who had previously been treated for leukaemia, 8.1%, and in children previously treated for craniopharyngioma, 5.6%. A lower frequency was found for those with a diagnosis of idiopathic short stature, 1.6%, and familial short stature, 0.9%. Kyphoscoliosis was more frequently seen in Turner's syndrome, and slipped epiphyses in adolescent individuals with growth hormone deficiency, especially following treatment for leukaemia. There were no de novo tumours reported but the frequencies of recurrence/patient year for leukaemia, solid cranial tumours and craniopharyngioma were 1.1%, 2.2% and 3.8% respectively. A low frequency of adverse events has been reported on the OZGROW database but subsets of patients may be at increased risk of musculoskeletal abnormalities during GH therapy. The frequency of tumour recurrence during therapy is not different from known rates of recurrence in individuals not treated with GH.

Insulin-resistant diabetes during growth hormone therapy in a child with SHORT syndrome

We report the case of a 13-year-old boy with SHORT syndrome, including lipoatrophy and insulin resistance, who developed diabetes mellitus while receiving growth hormone therapy. The diabetes persisted after cessation of exogenous growth hormone but oral hypoglycaemic therapy was successful and could be discontinued eight months later.

SHORT syndrome and insulin resistance

We describe a further case of SHORT syndrome. This girl shows nearly all the typical manifestations reported in patients with SHORT syndrome. However, at 14 years she presented with non-ketotic hyperglycemia. At 16 1/2 years, the diagnosis of diabetes mellitus secondary to severe insulin resistance was made by intravenous insulin challenge. Insulin resistant diabetes mellitus seems to be a new finding in SHORT syndrome, not previously described in this condition.