TY - JOUR

T1 - Identification of novel homozygous variants in FOXE3 and AP4M1 underlying congenital syndromic anophthalmia and microphthalmia

AU - Akbar, Warda

AU - Ullah, Asmat

AU - Haider, Nighat

AU - Suleman, Sufyan

AU - Khan, Fati Ullah

AU - Shah, Abid Ali

AU - Sikandar, Muhammad Atif

AU - Basit, Sulman

AU - Ahmad, Wasim

N1 - Publisher Copyright: © 2023 John Wiley & Sons Ltd.

PY - 2024

Y1 - 2024

N2 - Background: Anophthalmia and microphthalmia are severe developmental ocular disorders that affect the size of the ocular globe and can be unilateral or bilateral. The disease is found in syndromic as well as non-syndromic forms. It is genetically caused by chromosomal aberrations, copy number variations and single gene mutations, along with non-genetic factors such as viral infections, deficiency of vitamin A and an exposure to alcohol or drugs during pregnancy. To date, more than 30 genes having different modes of inheritance patterns are identified as causing anophthalmia and microphthalmia.Methods: In the present study, a clinical and genetic analysis was performed of six patients with anophthalmia and microphthalmia and/or additional phenotypes of intellectual disability, developmental delay and cerebral palsy from a large consanguineous Pakistani family. Whole exome sequencing followed by data analysis for variants prioritization and validation through Sanger sequencing was performed to identify the disease causing variant(s). American College of Medical Genetics and Genomics (ACMG) guidelines were applied to classify clinical interpretation of the prioritized variants.Results: Clinical investigations revealed that the affected individuals are afflicted with anophthalmia. Three of the patients showed additional phenotype of intellectual disability, developmental delays and other neurological symptoms. Whole exome sequencing of the DNA samples of the affected members in the family identified a novel homozygous stop gain mutation (NM_012186: c.106G>T: p.Glu36*) in Forkhead Box E3 (FOXE3) gene shared by all affected individuals. Moreover, patients segregating additional phenotypes of spastic paraplegia, intellectual disability, hearing loss and microcephaly showed an additional homozygous sequence variant (NM_004722: c.953G>A: p.Arg318Gln) in AP4M1. Sanger sequencing validated the correct segregation of the identified variants in the affected family. ACMG guidelines predicted the variants to be pathogenic.Conclusions: We have investigated first case of syndromic anophthalmia caused by variants in the FOXE3 and AP4M1. The present findings are helpful for understanding pathological role of the mutations of the genes in syndromic forms of anophthalmia. Furthermore, the study signifies searching for the identification of second variant in families with patients exhibiting variable phenotypes. In addition, the findings will help clinical geneticists, genetic counselors and the affected family with respect to prenatal testing, family planning and genetic counseling.

AB - Background: Anophthalmia and microphthalmia are severe developmental ocular disorders that affect the size of the ocular globe and can be unilateral or bilateral. The disease is found in syndromic as well as non-syndromic forms. It is genetically caused by chromosomal aberrations, copy number variations and single gene mutations, along with non-genetic factors such as viral infections, deficiency of vitamin A and an exposure to alcohol or drugs during pregnancy. To date, more than 30 genes having different modes of inheritance patterns are identified as causing anophthalmia and microphthalmia.Methods: In the present study, a clinical and genetic analysis was performed of six patients with anophthalmia and microphthalmia and/or additional phenotypes of intellectual disability, developmental delay and cerebral palsy from a large consanguineous Pakistani family. Whole exome sequencing followed by data analysis for variants prioritization and validation through Sanger sequencing was performed to identify the disease causing variant(s). American College of Medical Genetics and Genomics (ACMG) guidelines were applied to classify clinical interpretation of the prioritized variants.Results: Clinical investigations revealed that the affected individuals are afflicted with anophthalmia. Three of the patients showed additional phenotype of intellectual disability, developmental delays and other neurological symptoms. Whole exome sequencing of the DNA samples of the affected members in the family identified a novel homozygous stop gain mutation (NM_012186: c.106G>T: p.Glu36*) in Forkhead Box E3 (FOXE3) gene shared by all affected individuals. Moreover, patients segregating additional phenotypes of spastic paraplegia, intellectual disability, hearing loss and microcephaly showed an additional homozygous sequence variant (NM_004722: c.953G>A: p.Arg318Gln) in AP4M1. Sanger sequencing validated the correct segregation of the identified variants in the affected family. ACMG guidelines predicted the variants to be pathogenic.Conclusions: We have investigated first case of syndromic anophthalmia caused by variants in the FOXE3 and AP4M1. The present findings are helpful for understanding pathological role of the mutations of the genes in syndromic forms of anophthalmia. Furthermore, the study signifies searching for the identification of second variant in families with patients exhibiting variable phenotypes. In addition, the findings will help clinical geneticists, genetic counselors and the affected family with respect to prenatal testing, family planning and genetic counseling.

KW - anophthalmia

KW - AP4M1

KW - FOXE3

KW - novel variants

KW - sensory processing disorder

KW - whole exome sequencing

U2 - 10.1002/jgm.3601

DO - 10.1002/jgm.3601

M3 - Journal article

C2 - 37758467

AN - SCOPUS:85173094047

VL - 26

JO - Journal of Gene Medicine

JF - Journal of Gene Medicine

SN - 1099-498X

IS - 1

M1 - e3601

ER -