Nabais Sá-de Vries Syndrome Type 1 Case Report

Nabais Sá-de Vries Syndrome (NSDVS) is a neurodevelopmental disorder characterized by syndromic forms of intellectual disability. The condition is caused by de novo missense mutations in the SPOP gene, which encodes the speckle-type pox virus and zinc finger protein, located on chromosome 17q21.

Research indicates that NSDVS is an autosomal dominant inherited disease. The mutations in the SPOP gene are associated with two clinically distinct neurodevelopmental disorders, both of which contribute to the syndrome’s manifestation of intellectual disabilities.

Genetic Basis and Classification

The primary driver of the syndrome is the mutation of the speckle-type pox virus and zinc finger protein on chromosome 17q21. Because these are often de novo missense mutations, they occur spontaneously rather than being inherited from parents, though the inheritance pattern is classified as autosomal dominant.

The syndrome was first described in 2020. Since its identification, clinical reports have sought to categorize the specific phenotypic expressions of the disorder, including the distinction between different types of the syndrome, such as Nabais Sá-de Vries Syndrome Type 1 (NSDVS1).

Clinical and Neurodevelopmental Features

Patients with NSDVS present with a complex array of neuromotor, cognitive, adaptive, and behavioral features. Clinical insights published on February 7, 2025, in the American Journal of Medical Genetics Part A, detailed a case involving a novel pathogenic variant of the SPOP gene, highlighting the broad impact of the mutation on a patient’s development.

The clinical profile of the syndrome typically involves:

• Cognitive impairments and intellectual disability.
• Motor development challenges.
• Adaptive and behavioral difficulties.
• Neurovisual and ocular manifestations.

Ocular and Neurovisual Manifestations

A significant area of clinical focus has been the ocular manifestations associated with NSDVS1. A report published on June 15, 2022, in the International Journal of Molecular Epidemiology and Genetics, examined these features in a young male patient to better summarize the ocular characteristics found in affected individuals.

These neurovisual features are considered a key part of the syndrome’s clinical presentation, alongside the more prominent neurodevelopmental and cognitive delays. The inclusion of neurovisual assessments helps clinicians identify the syndrome and understand the full scope of the SPOP gene’s influence on development.

Case Reports and Diversity of Presentation

Medical literature continues to document the syndrome across diverse populations to refine the understanding of its expression. This includes a case report published in Cureus detailing Nabais Sá-de Vries Syndrome Type 1 in a Mexican girl.

The identification of novel pathogenic variants of the SPOP gene suggests that the syndrome may present with varying degrees of severity or different combinations of symptoms depending on the specific mutation. The ongoing documentation of these cases allows researchers to build a more comprehensive profile of the disorder’s behavioral and motor impact.

Current medical reporting emphasizes the necessity of genetic testing for the SPOP gene on chromosome 17q21 when patients present with the combination of intellectual disability and the specific neuromotor or neurovisual markers associated with Nabais Sá-de Vries Syndrome.