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 Table of Contents  
CASE REPORT
Year : 2022  |  Volume : 2  |  Issue : 1  |  Page : 211-213

Clinical and genetic aspects of a child with monilethrix and visual rehabilitation


1 Department of Paediatric Ophthalmology and Strabismus, Aravind Eye Hospital, Madurai, Tamil Nadu, India
2 Department of Genetics, Aravind Medical Research Foundation, Madurai, Tamil Nadu, India

Date of Submission07-Mar-2021
Date of Acceptance02-Aug-2021
Date of Web Publication07-Jan-2022

Correspondence Address:
Dr. Monisha Mohan
Department of Paediatric Ophthalmology and Strabismus, Aravind Eye Hospital, Madurai - 625 025, Tamil Nadu
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijo.IJO_542_21

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  Abstract 


Monilethrix is a rare genodermatosis, presented to us with predominant ocular manifestations. The affected proband was typically characterized by severe photophobia, defective vision, and hypotrichosis with brittle and stubby hair. Here, we report a rare case of a 9-year-old male child who has been affected by monilethrix with severe ocular complications including blepharitis, madarosis, and corneal pannus with lamellar cataract. The child has undergone cataract surgery and visual rehabilitation was provided with low-vision devices.

Keywords: Cataract, corneal pannus, hypotrichosis, monilethrix, regularly bended ribbon sign


How to cite this article:
Mohan M, Shetty S, Perumalsamy V, Prakash C, Sundaresan P. Clinical and genetic aspects of a child with monilethrix and visual rehabilitation. Indian J Ophthalmol Case Rep 2022;2:211-3

How to cite this URL:
Mohan M, Shetty S, Perumalsamy V, Prakash C, Sundaresan P. Clinical and genetic aspects of a child with monilethrix and visual rehabilitation. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 Jan 16];2:211-3. Available from: https://www.ijoreports.in/text.asp?2022/2/1/211/334957



Monilethrix is a rare hereditary skin disorder that follows both autosomal dominant and recessive traits. It is clinically represented as elliptical nodes and intermittent constrictions on the hair shafts leading to fragile hair.[1] Although the skin and hair manifestations in monilethrix have been well described, the ophthalmological manifestations associated with this rare genetic disorder are less known. Here, we described the visual rehabilitation and the genetic analysis of a rare case primarily affected by blepharitis, corneal pannus, bilateral cataracts associated with monilethrix.


  Case Report Top


A 9-year-old boy born to a nonconsanguineous family displayed bilateral cataracts with corneal pannus, esotropia, nystagmus, and hypotrichosis since birth. Child is studying in the fifth standard in regular school. He uses large print material and gets help from mother for his studies. Since he had been promoted to secondary education this year, he had difficulty in reading fine print and consulted us. Pedigree analysis showed that the proband had no previous medical history of monilethrix. Microscopic examination of the scalp revealed brittle, short stubby hair over the occipital and parietal region with no scarring; however, hairs were easily breakable. A similar picture was also noted over the eyebrows associated with madarosis [Figure 1]. Light microscopy of the hair from the scalp was examined, which revealed “regularly bended ribbon sign” [Figure 2].
Figure 1: Short stubby brittle hair over the scalp and eyebrows

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Figure 2: Light microscopy of hair showing alternating thickening and thinning of the hair shaft – “regularly bended ribbon sign”

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Ocular examination was difficult since child had severe photophobia. His unaided visual acuity examined in each eye was found to be CF @ 1 m with a dull retinoscopic reflex. He had a small angle esotropia of 10° with pendular nystagmus in both eyes. On anterior segment examination, he had blepharitis over the upper eyelids, madarosis over the eyebrows, corneal scarring with epithelial hyperplasia with 360° of superficial and deep vascularization in both eyes [Figure 3]. Iris appeared normal. Lens showed lamellar type of cataractous changes. B scan was performed which displayed normal posterior segment. The patient was planned for examination under anaesthesia along with lens extraction.
Figure 3: Intraoperative photograph of the corneal scarring with epithelial hyperplasia with vascularization

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Intraoperatively, corneal diameters were measured to be 12 mm both vertically and horizontally. Axial lengths were found to be 23.42 mm in the right eye and 23.04 mm in the left eye. Visualization was poor due to corneal pathology. A scleral tunnel was made for a cataract extraction due to corneal vascularization, careful capsulorrhexis was made, aspiration of the cortex was done, and was left aphakic. Scleral tunnel was sutured with two 10-0 nylon sutures [Figure 4]. The procedure was performed at two different sittings for the right and left eye.
Figure 4: Intraoperative photograph showing a scleral tunnel and lamellar type of cataractous changes

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Postoperatively, at 1 month follow-up, retinoscopy still showed a dull reflex due to corneal pathology. Bifocals were prescribed with +10 diopter spherical lenses with an add of +3 D for near. With a +10 diopter spherical lenses, he was able to read 3/60 tested on single letter logMAR chart at 1 m distance in each eye. Further, low-vision evaluation was carried out, wherein the distance visual acuity remained the same and with a hand held telescope of 4× magnification tried monocularly; he read 6/24 in each eye. Near vision was tested with a single letter chart with a 6× stand magnifier; he read N10. With a 3.5” digital video magnifier, he was able to read N6 continuous text with Lighthouse continuous text reading material and was prescribed to him. Contrast sensitivity was measured using a standard Pelli–Robson chart at 1 m distance and could read 0.90 in each eye. He was comfortable with a blackish gray tint for outdoor activities.


  Discussion Top


Monilethrix is a rare genetic disorder characterized by the beaded appearance of their hair strands, such as necklace beads. Monilethrix has also been associated with many other clinical features including koilonychia, syndactyly, cataract, blepharitis, pannus, and dental abnormality.[2] Mutations in the keratin genes KRT81, KRT83, and KRT86 followed autosomal dominant inheritance in monilethrix.[3] whereas the desmoglein 4 (DSG4) genetic mutation exhibit autosomal recessive inheritance pattern. In addition to these, de novo mutation was also reported in polish family.[4] DSG4 regulates the proliferation and differentiation of hair follicle keratinocytes. Several studies reported that compound heterozygous mutation and homozygous missense mutation in DSG4 gene frequently exhibit hypotrichosis and monilethrix disease phenotypes.[5] Our study has shown that the microscopic examination of the proband hair shaft showed a “regularly bended ribbon sign” characterized by alternating constriction (nonmedullated) and thickening (medullated) representing the defect and the actual hair diameter, respectively, which is a definitive feature noted in monilethrix patients[6] [Figure 4]. Targeted exome sequencing results displayed a heterozygous pathogenic missense variant in DSG4 gene (C1568T; p. P523L), which may contribute to the clinical phenotype of monilethrix in the affected individual. Although proband harbors only heterozygous mutation in DSG4 gene, incomplete penetrance, genetic heterogeneity, and variable disease expressivity are the factors frequently observed in monilethrix, which may be responsible for the disease progression in proband that subsequently reduces the likelihood of disease in their parents. Later, the child also experienced severe photophobia and grittiness in his eyes due to corneal involvement. Earlier reports demonstrated that monilethrix was associated with posterior subcapsular cataracts; however, our patient showed lamellar type of cataractous changes.[7] The genetic understanding of monilethrix with other ocular manifestations remains still poorly understood. No pathogenic variant was identified for the ocular phenotype's blepharitis, madarosis, and cornea pannus with lamellar cataract. Cataract surgery pose a major challenge in this patient due to poor visualization and therefore the intraocular lens could not be placed. For restoring the best possible vision, the proband was rehabilitated and lens extraction was performed. Aphakic glasses with near addition were provided, along with digital video magnifier. As the boy was interested to continue in regular school with the help of assistive devices and cooperation of teachers, we explained him the alternative educational methodology. Presently, he is learning to use computer with the help of special software – NonVisual Desktop Access and mobile with special application, which will help him to access recorded audio files for his learning. Video magnifier helped him utilize his functional vision, but since it had a smaller field of view and having to drag the magnifier over the book to complete each sentence which would cause fatigue, he was asked to use it for shorter period of time and recorded audio files were also made available to him from our visual rehabilitation center. He could also get scribe assistance during examination as per government norms. The rehabilitation team is doing the follow-up services to improve his quality of life.


  Conclusion Top


This rare case of monilethrix in a child with blepharitis, corneal pannus, bilateral cataract demonstrates the ophthalmic features of this hereditary skin disease.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Holani AR, Haridas NS, Shah NG, Chaudhari N. Monilethrix: A rare case diagnosed by dermoscopy. Indian J Paediatr Dermatol 2020;21:56-8.  Back to cited text no. 1
  [Full text]  
2.
Rajamohanan RR, Behera B, Nagendran P, Malathi M. Monilethrix: A report of three cases in children confirmed with dermoscopy. Indian Dermatol Online J 2020;11:65-7.  Back to cited text no. 2
[PUBMED]  [Full text]  
3.
Redler S, Pasternack SM, Wolf S, Stienen D, Wenzel J, Nöthen MM, et al. A novel KRT86 mutation in a Turkish family with monilethrix, and identification of maternal mosaicism. Clin Exp Dermatol 2015;40:781-5.  Back to cited text no. 3
    
4.
Brzezinski P, Cywinska E. Discreet monilethrix: De novo mutation on the example of polish families. Int J Trichology 2017;9:90-1.  Back to cited text no. 4
    
5.
Farooq M, Ito M, Naito M, Shimomura Y. A case of monilethrix caused by novel compound heterozygous mutations in the desmoglein 4 (DSG4) gene. Br J Dermatol 2011;165:425-31.  Back to cited text no. 5
    
6.
Sharma VK, Chiramel MJ, Rao A. Dermoscopy: A rapid bedside tool to assess monilethrix. Indian J Dermatol Venereol Leprol 2016;82:73-4.  Back to cited text no. 6
[PUBMED]  [Full text]  
7.
Erbagci Z, Erbagci I, Erbagci H, Erkılıc S, Tuncel AA. Severe monilethrix associated with intractable scalp pruritus, posterior subcapsular cataract, brachiocephaly, and distinct facial features: A new variant of monilethrix syndrome? Pediatr Dermatol 2004;21:486-90.  Back to cited text no. 7
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]



 

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