Hypohidrotic Ectodermal Dysplasia: A Rare Disorder With Bilateral Infantile Glaucoma

Papillon-Lefevre syndrome in twelve Egyptian patients: Five novel CTSC variants and functional characterization of a missense variant and its effect on splicing

OBJECTIVES

describing the clinical features of twelve Egyptian patients with Papillon-Lefever syndrome (PLS). Five novel mutations in the cathepsin C (CTSC) gene are introduced and the phenotype of the syndrome is expanded by the identification of new clinical features.

DESIGN

the clinical, oro-dental data of twelve Egyptian patients from seven unrelated families are described. Sequence analysis of the CTSC gene was performed to identify the causative mutaions.

RESULTS

Typical PLS features were presented in all patints but with variable severity. One patient showed atypical dental features including dental structural defect, minimal periodontitis, severe gingivitis, and delayed closure of root apices. Another patient presented with arachnodactyly, dystrophic nails, and buphthalmos in the right eye secondary to uncontrolled congenital glaucoma. Mutational analysis of CTSC gene revealed seven distinct homozygous variants including five novel ones: c.285_286delGT (p.Leu96GlufsTer2), c .302 G>C (p.Trp101Ser), c.622_628delCACAGTC (p.H208Efs*11), c.1331delinsAAAAA (p.G444Efs*4) and c .1343 G>A (p.Cys448Tyr). The previously reported missense variant c .757 G>A (p.Ala253Thr) was found in one patient. This variant is very close to the splice region and by functional studies, we proved that it results in exon skipping and early protein truncation (p.R214Sfs*46).

CONCLUSION

We report five novel CTSC variants and describe rare and unusual associated clinical and dental findings such as dental structural defects, delayed closure of root apices, and congenital glaucoma. Therefore, our results expand both the phenotypic and mutational spectrum of PLS.

Extended Overview of Ocular Phenotype with Recent Advances in Hypohidrotic Ectodermal Dysplasia

The term ectodermal dysplasias (EDs) describes a heterogeneous group of inherited developmental disorders that affect several tissues of ectodermal origin. The most common form of EDs is hypohidrotic ectodermal dysplasia (HED), which is characterized by hypodontia, hypotrichosis, and partial or total eccrine sweat gland deficiency. HED is estimated to affect at least 1 in 17,000 people worldwide. Patients with HED have characteristic facies with periorbital hyperpigmentation, depressed nasal bridge, malar hypoplasia, and absent or sparse eyebrows and eyelashes. The common ocular features of HED include madarosis, trichiasis, and ocular chronic surface disease due to dry eye syndrome, which manifests clinically with discomfort, photophobia, and redness. Dry eye is common in HED and results from a combination of ocular surface defects: mucus abnormalities (abnormal conjunctival mucinous glands), aqueous tear deficiency (abnormalities in the lacrimal gland) and lipid deficiency (due to the partial or total absence of the meibomian glands; modified sebaceous glands with the tarsal plate). Sight-threatening complications result from ocular surface disease, including corneal ulceration and perforation with subsequent corneal scarring and neovascularization. Rare ocular features have been reported and include bilateral or unilateral congenital cataracts, bilateral glaucoma, chorioretinal atrophy and atresia of the nasolacrimal duct. Recognition of the ocular manifestations of HED is required to perform clinical surveillance, instigate supportive and preventative treatment, and manage ocular complications.

Potential Risks of Corneal Refractive Surgery in Patients with Ectodermal Dysplasia

Ectodermal dysplasia (ED) involves the aberrant development of at least two ectodermal derivatives, such as skin, teeth, hair, sweat glands, and ocular tissue. The group of over 200 conditions is commonly classified into two major types: hypohidrotic/anhidrotic ED, in which sweat glands are either absent or significantly reduced, and hidrotic ED, in which sweat glands are normal. Ocular manifestations pertinent to patients undergoing corneal vision correction surgery include multifaceted dry eye syndrome, corneal pathology, such as recurrent erosions, scars, neovascularization, and limbal stem cell deficiency, and early-onset cataracts and glaucoma. In this article we discuss the current understanding of ED and offer factors to consider when these patients are seeking corneal refractive surgery.

Central nervous system variations and abnormalities in anhidrotic ectodermal dysplasia (AED): neuroimaging findings

BACKGROUND

Anhidrotic ectodermal dysplasia (AED) is a rare, mostly X-linked recessive genodermatosis, characterized by congenital defects of ectodermal derivative structures as the central nervous system (CNS) is primarily ectodermal in origin.

PURPOSE

To evaluate CNS variations and abnormalities in AED.

MATERIAL AND METHODS

A retrospective analysis was made of the neurological and neuroimaging findings of 17 children (12 boys, 5 girls; median age = 8 years; age range = 2-14 years) diagnosed with AED in our pediatric clinics during 2008-2016. The pattern of CNS variation and abnormalities were evaluated by comparing of these findings with an age- and gender-matched healthy control group with no family history.

RESULTS

Of the 17 AED cases identified on the basis of neuroimaging findings, 6 (35.3%) were seen to be normal. Associated CNS variation and abnormalities including cavum septum pellucidum (35.3%), callosal dysgenesis (11.8%), prominent Virchow-Robin spaces (64.7%), cortical sulcal dilation (41.1%), mega cisterna magna (35.3%), focal cortical dysplasia (11.8%), and delayed myelination (58.8%) were observed in 11 (64.7%) children with AED.

CONCLUSION

AED suggests a spectrum of CNS variation and abnormalities, presenting with neurological and neuroimaging findings, demonstrated in the embryonic surface- and neuro-ectoderm derived structures. The results of this study suggest that CNS variation and abnormalities might be associated with AED.