# Chromosome 1p31.1 Deletion: A Case With Developmental Delay, Hypotonia, Cryptorchidism, Abnormal Oral Frenulum, and Feet Deformity

## TL;DR

This paper reports a rare chromosomal deletion case with unique features like abnormal oral frenulum and feet deformity.

## Contribution

The study adds a new case of 1p31.1 deletion with a unique combination of clinical features, including thickened oral frenulum.

## Key findings

- A 14.385 Mb deletion in 1p31.1 encompassing 41 genes was identified.
- The case exhibited microcephaly, hypotonia, developmental delay, and flat feet.
- Congenital thickening of the lingual and labial frenulum was observed, a feature not previously associated with this deletion.

## Abstract

Deletions within the chromosomal locus 1p31.1 are rare, with only a limited number of documented cases. The typical clinical presentation includes intellectual disability, failure to thrive, and craniofacial abnormalities. Some cases may also present with cardiac, gastrointestinal, and genitourinary malformations. Variability in deletion size contributes to a broad spectrum of clinical phenotypes, and a comprehensive understanding of the syndrome's manifestations is still evolving. This case study aims to provide additional insights into 1p31.1 microdeletion syndrome, enhancing knowledge of its genetic and phenotypic characteristics to improve recognition by clinicians. Here, we report a case featuring a 14.385 Mb deletion isolated to the 1p31.1 region, encompassing 41 genes. The deletion manifested with microcephaly, distinctive facial morphology, hypotonia, developmental delay, bilateral cryptorchidism, and flat feet. Notably, our case also exhibited congenital thickening of the lingual and labial frenulum, a trait not typically associated with this deletion.