Identification of a novel GPR143 mutation in X-linked ocular albinism with marked intrafamilial phenotypic variability

Mutation of GPR143 Associated With Ocular Albinism Type 1, Intellectual Disability, and Schizophrenia: The Complex Biological and Social Interactions Between Genetic Syndromes and Mental Illness

Copy number variations, which manifest primarily as deletions and duplications, contribute significantly to the genetic risk of schizophrenia. Specific syndromes associated with copy number variations, exemplified by the 22q11 deletion syndrome, confer both congenital abnormalities and an elevated risk of schizophrenia. We report the case of a patient with a deletion of exons 2 through 8 of GPR143. In addition to having the ophthalmologic disorder ocular albinism type 1 (OA1), a well-established consequence of mutations of GPR143, the patient is also intellectually impaired and impulsive, and he developed schizophrenia at age 15. Psychiatric manifestations of OA1 have not previously been reported, yet remain plausible, as the GPR143 protein is widely distributed in the brain and may function as an L-DOPA receptor. However, the patient described here also had a family history of psychiatric disorders independent of OA1, in utero exposure to heroin and cocaine, and challenging family circumstances. We suggest that the relationship between his GPR143 mutation and his psychiatric disorders is complex. The mutation may have directly contributed to his cognitive and psychiatric disorders, but we also suspect that OA1, present in multiple family members, contributed to multigenerational familial instability. Further, OA1 likely exacerbated our patient's cognitive and social impairment by interfering with his education, while his neuropsychiatric status frequently interfered with the assessment and treatment of his OA1. We conclude that the psychiatric and nonpsychiatric manifestations of a genetic syndrome are best managed in parallel and that psychiatrists and other mental health providers may be in the best position to assure that patients receive appropriate genetic and medical care.

Ocular findings and genomics of X-linked recessive disorders: A review

Advent of new sequencing technologies and modern diagnostic procedures has opened the door for a deeper understanding of disorders about which little was known previously. Discovery of novel genes, new genetic variants in previously known genes and better techniques of functional validation has immensely contributed to unraveling the molecular basis of genetic disorders. Availability of knockout animal models like the zebrafish and gene editing tools like CRISPR-Cas9 has elucidated the function of many new genes and helped us to better understand the functional consequences of various gene defects. This has also led to better diagnosis and therapeutic interventions. In this context, a good body of research work has been done on X-linked recessive disorders with ocular findings. This review will focus on ocular and genetic findings of these rare disorders. To our knowledge, this is the first comprehensive review encompassing ocular and genomic spectrum of X-linked recessive disorders.

Clinical and Mutation Spectrum of Autosomal Recessive Non-Syndromic Oculocutaneous Albinism (nsOCA) in Pakistan: A Review

Oculocutaneous albinism (OCA) is an autosomal recessive syndromic and non-syndromic defect with deficient or a complete lack of the melanin pigment. The characteristics of OCA appears in skin, hair, and eyes with variable degree of pigmentation. Clinical manifestations of OCA include nystagmus, photophobia, reduced visual acuity, hypo-plastic macula, and iris trans-illumination. There are eight OCA types (OCA1–8) documented with non-syndromic characteristics. Molecular studies identified seven genes linked to the OCA phenotype (TYR, OCA2, TYRP1, SLC45A2, SLC24A5, C10orf11, and DCT) and one locus (OCA5) in consanguineous and sporadic albinism. The complications of OCA result in skin cancer and variable syndromes such as Hermansky–Pudlak syndrome (HPS) Chediak–Higashi syndrome (CHS). In the Pakistani population, autosomal recessive non-syndromic OCA is common and is associated with a large number of consanguineous families, and mutations in genes of non-syndromic types are reported. This review highlights the updates on the genetic mutation of OCA genes reported from Pakistani families. Several studies reported the genetic mutations in OCA1, OCA2, OCA3, OCA4, and OCA6 albinism in Pakistani families. A locus, OCA5, was also reported from the Pakistani population, but the gene has not been identified. A new type of OCA8 was identified due to the DCT gene mutation, and it is also reviewed here.

Identifying psychosocial challenges and introducing coping strategies for people with albinism

Albinism refers to a group of genetic disorders that, following genetic mutations, lead to impaired melanin production, resulting in skin allergies and visual impairment in affected people. Visual impairment brings not only physical limitations and challenges but also many social problems, including psychosocial challenges, leading to different experiences in the lives of these people. To this end, using a qualitative content analysis approach, the present study aimed to identify psychosocial challenges and introduce coping strategies for people with albinism living in Tehran in 2021. The participants were people with albinism aged 20 to 40 years in Tehran. The participants were selected from among members of the Iranian Albinism Association (AMAL) using purposive sampling. The data were saturated through semi-structured interviews with 20 participants in the research sample. The collected data were analyzed using conventional content analysis. Analysis of the participants’ experiences revealed three main themes: (1) The challenges and difficulties of living with albinism, (2) welfare, specialized facilities, and support seeking, and (3) strategies for coping with psychosocial challenges. According to the findings, albinism, due to its limitations, brings many bitter and painful experiences in education, job finding, and marriage for affected patients. The condition is also associated with some limitations such as visual impairment affecting various aspects of the patient’s life and different developmental periods. Each person may have different interpretations of their challenges and thus seek unique strategies for coping with the challenges. The findings of this study can have some implications for mental health professionals and managers of relevant institutions and to become aware of the nature and complications of albinism, the challenges faced by people with albinism, and the special needs of these people. Findings from this study can be used to identify the relationship between albinism, the challenges of living with albinism, and the special needs of these individuals, by mental health professionals, related institutions, and psychosocial environments.

Novel Biallelic Variants and Phenotypic Features in Patients with SLC38A8-Related Foveal Hypoplasia

Biallelic pathogenic variants in solute carrier family 38 member 8, SLC38A8, cause a pan-ocular autosomal recessive condition known as foveal hypoplasia 2, FVH2, characterised by foveal hypoplasia, nystagmus and optic nerve chiasmal misrouting. Patients are often clinically diagnosed with ocular albinism, but foveal hypoplasia can occur in several other ocular disorders. Here we describe nine patients from seven families who had molecularly confirmed biallelic recessive variants in SLC38A8 identified through whole genome sequencing or targeted gene panel testing. We identified four novel sequence variants (p.(Tyr88*), p.(Trp145*), p.(Glu233Gly) and c.632+1G>A). All patients presented with foveal hypoplasia, nystagmus and reduced visual acuity; however, one patient did not exhibit any signs of chiasmal misrouting, and three patients had features of anterior segment dysgenesis. We highlight these findings in the context of 30 other families reported to date. This study reinforces the importance of obtaining a molecular diagnosis in patients whose phenotype overlap with other inherited ocular conditions, in order to support genetic counselling, clinical prognosis and family planning. We expand the spectrum of SLC38A8 mutations which will be relevant for treatment through future genetic-based therapies.