Mucolipidosis Type IV in Omani Families with a Novel MCOLN1 Mutation: Search for Evidence of Founder Effect.

Mucolipidosis Type IV (MLIV) is caused by a deficiency of the mucolipin cation channel encoded by Mucolipin TRP Cation Channel 1 gene (MCOLN1). It is a slowly progressive neurodevelopmental and neurodegenerative disorder causing severe psychomotor developmental delay and progressive visual impairment, which is often misdiagnosed as cerebral palsy. We describe six patients with MLIV from two Omani families with a novel c.237+5G>A mutation in the MCOLN1 gene predicted to affect mRNA splicing. Mutation screening with a high-resolution melting (HRM) assay in a large population sample did not detect this mutation in control subjects. This report highlights the importance of considering MLIV in the differential diagnosis of patients in a pediatric age group with cerebral palsy-like presentation. Although the same rare mutation was seen in two apparently unrelated families, this was not seen in the sample screened from the general population. The HRM assay provides a cost-effective assay for population screening for the c.237+5G>A mutation.

Ophthalmic findings as clues for early diagnosis of Vici syndrome in a neonate.

AIM: To report the earliest diagnosis of Vici syndrome in a three-week-old Omani girl. METHODS: A three-week-old baby girl with blond hair and agenesis of the corpus callosum was born to consanguineous parents. An older sibling with similar findings had died at the age of six months with recurrent seizures and aspiration pneumonia without a diagnosis of the underlying systemic condition. After a standard ophthalmic and comprehensive systemic evaluation, full sequencing of the EPG5 gene was carried out. RESULTS: The findings of bilateral anterior polar cataracts and oculocutaneous albinism in the child with agenesis of corpus callosum raised a suspicion of Vici syndrome. Immunology, neurology, cardiology, and genetic consultations were requested and revealed the presence of immunodeficiency, psychomotor retardation, and hypertrophic cardiomyopathy. Full sequencing of the EPG5 gene led to the detection of a homozygous c.6084 G > A (Trp2028Ter) mutation, confirming the diagnosis of Vici syndrome. Parental heterozygosity was confirmed. On follow-up, progressive microcephaly, failure to thrive, and significant developmental delay were noted, and a clinical decision not to resuscitate was made at the age of 22 months. CONCLUSIONS: We report the earliest diagnosis of Vici syndrome in the literature. Ophthalmic findings are a cardinal feature of this condition. The diagnosis should be considered in infants with hallmark features of oculocutaneous albinism, cataracts, and agenesis of the corpus callosum. Vici syndrome has a very poor prognosis due to progressive neuroregression superimposed on the neurodevelopmental anomaly.

Co-inheritance of the membrane frizzled-related protein ocular phenotype and glycogen storage disease type Ib.

AIM: To report co-occurrence of two rare recessive conditions, the membrane frizzled-related protein (MFRP)-related ocular phenotype and glycogen storage disease type 1b (GSD-1b), in three siblings in an Omani family. BACKGROUND: Biallelic mutations in the MFRP gene (chromosome 11q23) result in a distinct ocular phenotype characterized by retinitis pigmentosa, foveoschisis, optic nerve head drusen, and posterior microphthalmos. GSD-1b is an autosomal-recessive disorder caused by mutations in SLC37A4 gene located in the same chromosomal region. METHODS: An Omani family with three siblings diagnosed with GSD-1b presented with ocular manifestations of progressive visual impairment and diminution of night vision. All siblings underwent a standard ophthalmic and clinical genetic evaluation. Full sequencing of the MFRP and SLC37A4 genes and haplotype analysis was carried out. RESULTS: The three children (2F:1M) aged 13, 17, and 18 years were born to consanguineous parents. Their best-corrected visual acuity ranged from 20/60 to 20/15. Ophthalmic exam revealed bilateral optic disc drusen, foveoschisis, and pigmentary retinopathy, hyperopia of +12 to +15.5 diopters, and decreased axial length (15.8-16.39 mm) in all affected siblings. Full-field electroretinography showed rod-cone dysfunction. Sequence analysis revealed two novel variants in a homozygous state in the SLC37A4 and MFRP genes in all the affected patients. CONCLUSIONS: We report the MFRP-related ocular phenotype in three siblings with GSD-1b. Molecular genetic studies identified novel mutations in the MFRP and SLC37A4 genes. Co-inheritance of a haplotype harboring mutations in both loci on chromosome 11q23 resulted in co-occurrence of the MFRP-related ocular phenotype and GSD-1b. This has not been reported previously.

Septo-optic dysplasia complex: Clinical and radiological manifestations in Omani children.

BACKGROUND: Septo-optic dysplasia (SOD), also known as de-Morsier's syndrome, is a rare disorder characterized by any combination of optic nerve hypoplasia (ONH), pituitary gland hypoplasia, and midline abnormalities of the brain including absence of septum pellucidum and corpus callosum dysgenesis. It is typically diagnosed in infancy and has a variable presentation that includes visual, neurologic, and/or hypothalamic-pituitary endocrine deficits. PURPOSE: To demonstrate the ophthalmic, endocrine, and neurologic spectrum of SOD in five Omani children and address the crucial role of high-resolution neuroimaging for its early and accurate diagnosis. MATERIALS AND METHODS: A retrospective chart review was performed in 2010 of all children in the pediatric ophthalmology database of Sultan Qaboos University Hospital (SQUH) who were diagnosed to have ONH. All relevantdemographic, ophthalmic, neurologic, endocrine, and neuro-radiological manifestations were recorded in a data collection form. All previous neuroimaging results were reviewed by a neuro-radiologist. RESULTS: Five patients (four males, one female) with the diagnosis of ONH were included in the study. They presented during the period 1998-2008. All patients were born at term, with normal birth weights to healthy mothers with insignificant antenatal history. Age at presentation ranged from three months to one year. Manifestations at presentation included severe visual impairment (5/5), neonatal hypoglycemia (3/5), seizure disorder (2/5), and failure to thrive (4/5). ONH was bilateral in 3/5 patients and unilateral in (2/5). Brain and orbit imaging revealed varying anomalies in all patients. These included absent septum pellucidum (3/5), severe corpus callosum agenesis (1/5), ectopic pituitary (5/5), falx cerebri deficiency (1/5), optic nerve hypoplasia (5/5), optic chiasmal hypoplasia (5/5), and olfactory tract hypoplasia (1/5). Endocrine deficits were detected in 4/5 patients (3 with panhypopituitarism, and 1 with growth hormone deficiency) and necessitated replacement therapy. CONCLUSION: SOD is a clinically heterogeneous disorder with a wide spectrum of ophthalmic, endocrine, and neurologic manifestations. All features might not be present in a single patient. A high consanguinity rate and lack of history of alcohol and drug use were observed in our cohort. Most affected children present first to the pediatrician with failure to thrive. Radiological confirmation of ONH necessitates high-resolution imaging and interpretation by an experienced neuro-radiologist. In our cohort, all patients with ONH had associated optic chiasmal hypoplasia. Early detection and treatment reduces disease-related morbidity, and can be life saving.

Oral propranolol for the treatment of periorbital infantile hemangioma: a preliminary report from oman.

PURPOSE: To investigate the efficacy and safety of oral propranolol in the management of periorbital infantile hemangioma in four subjects. MATERIALS AND METHODS: Consecutive patients who presented with periorbital capillary hemangioma with vision-threatening lesions were prospectively enrolled in this study between January 2009 and October 2010. All subjects underwent treatment with 2 mg/kg/day oral propranolol. All subjects underwent ocular, systemic, and radiologic evaluations before treatment and at periodic intervals after starting therapy. Side effects from therapy were also evaluated. RESULTS: Four subjects, between 3 months and 19 months of age, with periorbital hemangioma were enrolled in this study. Two subjects had been previously treated with oral corticosteroids with unsatisfactory response. All subjects had severe ptosis, with the potential for deprivation amblyopia. Three subjects had orbital involvement. After hospital admission, oral propranolol was initiated in all subjects under monitoring by a pediatric cardiologist. Subsequent therapy was performed with periodic out-patient monitoring. All subjects had excellent response to treatment, with regression of periorbital and orbital hemangioma. There were no side effects from therapy. CONCLUSIONS: Oral propranolol for periorbital hemangioma was effective in all the four subjects. Oral propranolol may be appropriate for patients who are nonresponsive to intralesional or systemic steroids. In patients with significant orbital involvement and lesions causing vision-threatening complications, oral propranolol can be the primary therapy.