Case report on SHORT syndrome

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.

Activation of PI3K signaling prevents aminoglycoside-induced hair cell death in the murine cochlea

Loss of sensory hair cells of the inner ear due to aminoglycoside exposure is a major cause of hearing loss. Using an immortalized multipotent otic progenitor (iMOP) cell line, specific signaling pathways that promote otic cell survival were identified. Of the signaling pathways identified, the PI3K pathway emerged as a strong candidate for promoting hair cell survival. In aging animals, components for active PI3K signaling are present but decrease in hair cells. In this study, we determined whether activated PI3K signaling in hair cells promotes survival. To activate PI3K signaling in hair cells, we used a small molecule inhibitor of PTEN or genetically ablated PTEN using a conditional knockout animal. Hair cell survival was challenged by addition of gentamicin to cochlear cultures. Hair cells with activated PI3K signaling were more resistant to aminoglycoside-induced hair cell death. These results indicate that increased PI3K signaling in hair cells promote survival and the PI3K signaling pathway is a target for preventing aminoglycoside-induced hearing loss.

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.

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.

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.