Possible hypomyelination and congenital cataract extremely rare case from rural part of Ethiopia: a case report

¹Faculty of Medicine, Amhara Regional Health Bureau, General Hospital, South Wollo, Ethiopia, ²Faculty of Medicine, Wollo University, Comprehensive Specialized Hospital, Dessie, Ethiopia, ³Johns Hopkins Program for International Education in Gynecology and Obstetrics, Ethiopia Country Office, Gonder, Ethiopia, ⁴Department of Medicine, College of Health Sciences, Woldia University, Woldia, Ethiopia

^&Corresponding author
Andualem Endrias Yesuf, Faculty of Medicine, Amhara Regional Health Bureau, General Hospital, South Wollo, Ethiopia

Introduction    

Lack of hyccin, a membrane protein crucial in both central and peripheral myelination, causes hypomyelination and congenital cataract (HCC), an autosomal recessive white matter condition [1]. It involves an inherited disorder that affects the vision as well as the nervous system. This disease falls under the category of inherited conditions known as leukoencephalopathies [1]. This autosomal recessive condition is brought on by a homozygous mutation in the FAM126A gene. Mutations in the FAM126A gene result in hypomyelination and congenital cataracts. The FAM126A gene delivers instructions for creating the hycin protein, a role that is not entirely understood [2] patients with this disease usually have normal development throughout the first year of life by the age of 1 year they start to face slow development. The majority of affected children begin to walk between the ages of 1 and 2, but they frequently require some sort of assistance. Over time, they acquire neurologic symptoms like wasting and weakness in their legs' muscles, and many affected individuals eventually need wheelchair assistance. Some people's walking is further hampered by weakness in their trunk muscles and a gradual abnormal curvature of their spine (scoliosis). Peripheral neuropathy is a common symptom of hypomyelination and congenital cataract in affected individuals. Additionally, those who suffer frequently have dysarthria, a speech disorder, and a mild to severe intellectual handicap [3]. We presented a rather uncommon case of probable hypomyelination and congenital cataract here.

Patient and observation     

Patient information: a male child aged one year and two months complained of not growing as expected for his age, not being able to hold items, and being unable to stand or walk. The second sibling's same condition has a notable family history. The family consisted of five siblings, two of whom were male and the other four females. The second child in the family, a male, came with similar symptoms at age one, including bilateral lens clouding, developmental delay, and aberrant spine curvature. He later passed away. Sisters are healthy otherwise no further signs or case mix index chronic medical illness (CMI) . There was no noteworthy medical background.

Clinical findings: bilateral cataract (congenital), gross developmental delay and scoliosis. Cardiac and other examinations were normal. Weight=3.5kg, length=53cm (Figure 1, Figure 2).

Diagnostic assessment:the diagnosis was considered by the patient's typical presentation, similar illness in the sibling, typical physical examination findings (developmental delay, bilateral congenital cataracts, scoliosis) and X-ray findings, which are strong evidence to consider the diagnosis. A brain MRI was considered for confirmation of the diagnosis, but the unavailability of the modality and financial incapability make it impossible. Other investigations, including echo, were normal (Figure 3).

Diagnosis: the diagnosis of HCC would be confirmed by a brain MRI showing hypomyelination with bilateral congenital cataracts. Unfortunately, an MRI of the brain was not done, and we are unable to confirm hypomyelination. We have evidence of scoliosis, cataracts, and developmental delay, strongly supporting the diagnosis.

Therapeutic interventions: nutritional support and infection prevention. No specific treatment.

Patient perspective: patient is not expecting a different treatment and disease course than their previous child.

Informed consent: the child’s family permitted the authors to publish this case report.

Discussion     

Congenital cataract and hypomyelination of the central and peripheral nervous systems are two distinct symptoms of a rare autosomal recessive white matter condition called hypomyelination and congenital cataract [4]. Previous case reports have described the clinical signs of bilateral congenital cataract, developmental delay, and gradually developing neurological impairment with spasticity, cerebellar ataxia, and mild-to-moderate mental retardation [4]. According to the findings of three siblings who had the same clinical symptoms as our case, these children had bilateral congenital cataracts and a gradual neurological impairment with peripheral neuropathy. Neurophysiological investigations revealed sensorimotor peripheral polyneuropathy, whereas brain magnetic resonance imaging (MRI) revealed diffuse hypomyelination [5]. In our situation, even if we have no evidence of hypomyelination confirmed by MRI because of financial reasons and inaccessibility, evidence of detailed history (sibling death following similar presentation), physical examinations (congenital cataracts), and imaging of the spine (scoliosis) strongly supports this rare syndrome, and a diagnosis of possible HCC (hypomyelination and congenital cataract) was made. Toddlers presenting with a syndrome of congenital bilateral cataracts, scoliosis, gross developmental delay, and possible hypomyelination are very rare.

Conclusion     

Toddlers presenting with a syndrome of congenital bilateral cataracts, scoliosis, gross developmental delay and possible hypomyelination are very rare. Moreover, the inaccessibility of advanced molecular and neuroradiologic investigations in Africa and many other continents made the diagnosis impossible. A high index of suspension is required for the diagnosis and early consideration of diagnosis can lead to rapid facilitation for confirmatory studies, if accessible. It is henceforth, important not to overlook the diagnosis of HCC, even if there are no molecular studies and neuroradiologic imaging.

Competing interests     

The authors declare no competing interest.

Authors' contributions     

All the authors have read and agreed to the final manuscript.

Figures     

Figure 1: shows bilateral congenital cataracts

Figure 2: shows abnormal curvature of the spine (scoliosis)

Figure 3: X-ray of the spine showing scoliosis

References