A Rare Case of Prenatal Short-Rib Thoracic Dysplasia 11 Subtype With Compound Heterozygous Variants in the DYNC2I2 Gene - Presenting Polydactyly and Shortened Limbs

Sep 29, 2026

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DYNC2I2-related Short-Rib Thoracic Dysplasia 11 can show prominent limb shortening and polydactyly prenatally, often with less obvious classic thoracic abnormalities on ultrasound. This report emphasizes clinical heterogeneity within DYNC2I2-associated disease and supports genetic testing to achieve accurate diagnosis and provide appropriate counseling. The discussion highlights the role of DYNC2I2 in ciliary intraflagellar transport, linking genotype to developmental features and variable severity.

LanguageEnglish

CategoryHealthcare

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Pages6

Reading Time15 min

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Introduction

Genetic basis and ciliary function

Clinical heterogeneity and phenotype variability

Prenatal presentation gap

Clinical Case Reports CASE REPORT OPEN ACCESS A Rare Case of Prenatal Short-Rib Thoracic Dysplasia 11 Subtype With Compound Heterozygous Variants in the DYNC2I2 Gene: Presenting Polydactyly and Shortened Limbs Zhihui Wang1 | Heqin Guan2 | Ximei Li1 | Jielan Liao3 | Yong Pan4 | Xueqin Dong5 | Xutao Hong4,6 1Department of Gynecology and Obstetrics, Wenzhou Central Hospital, Zhejiang, China | 2Department of Reproductive Medicine, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Zhejiang, China | 3Department of Radiology, Wenzhou Central Hospital, Zhejiang, China | 4Department of Central Laboratory, Wenzhou Central Hospital, Zhejiang, China | 5Department of Ultrasound, Wenzhou Central Hospital, Zhejiang, China | 6Yikon Genomics co. , Ltd, Shanghai, China Correspondence: Xutao Hong ([hongxt@zju.edu.cn](hongxt@zju.edu.cn)) Received: 27 April 2025 | Revised: 21 October 2025 | Accepted: 10 December 2025 Keywords: clinical heterogeneity | DYNC2I2 | genetic variants | polydactyly | prenatal diagnosis | short rib thoracic dysplasia (SRTD) | ABSTRACT
DYNC2I2-related Short-Rib Thoracic Dysplasia 11 can present prenatally with prominent limb shortening and polydactyly asthe primary ultrasound findings, while classic thoracic abnormalities may be subtle. This case highlights the condition's clinical heterogeneity and underscores the importance of genetic testing for accurate diagnosis and counseling. | | | --- | --- | | 1 | Introduction | with most cases linked to pathogenic variants in the DYNC2H1 gene, which is responsible for the more common subtypes, | | Skeletal dysplasias encompass a diverse group of genetic disor- | SRTD3 [2–4]. However, a less prevalent variant, associated with | | ders characterized by abnormalities in bone and cartilage devel- | the DYNC2I2 (formerly known as WDR34) gene, leads to the | | opment, leading to significant variations in skeletal morphology and function. These conditions are often associated with a range | rarer subtype known as SRTD11 . | | of clinical manifestations, including limb shortening, polydac- | The DYNC2I2 gene encodes the WD repeat-containing protein | | tyly, and thoracic constriction. According to the 2023 Nosology | 34, which is a component of the mammalian dynein motor- | | of Genetic Skeletal Disorders, Short-Rib Dysplasia (SRD) group | based intraflagellar transport (IFT) machinery. This machin- | | (formerly Short-Rib Polydactyly Syndrome, SRPS) falls under | ery is critical for the assembly and maintenance of cilia, which | | the category of “skeletal disorders caused by abnormalities of | are essential organelles for various signaling pathways cru- | | cilia or ciliary signaling”(NOS10-0040) and is associated with 33 different genes [1] . Among the various subtypes of skeletal | cial for normal development and survival (NCBI Reference: NM_ 052844.3) . Pathogenic variants in DYNC2I2 disrupt ciliary | | dysplasia, Short-Rib Thoracic Dysplasia (SRTD) represents a | function, leading to the constellation of features seen in ciliop- | | particularly severe form, typically characterized by short ribs and a narrowed thorax, which often results in life-threatening | athies like SRTD. | | respiratory complications in affected neonates. The incidence of | The identification of genetic variants associated with skele- | | SRTD is estimated to be approximately 1 in 100,000 live births, | tal dysplasia has been greatly facilitated by advancements in | | Zhihui Wang and Heqin Guan have contributed equally to this work. | | | This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
© 2026 The Author(s). Clinical Case Reports published by John Wiley & Sons Ltd. | | Clinical Case Reports, 2026; 14:e71708 1 of 6 [htt

FAQs

What prenatal ultrasound findings are most prominent in this DYNC2I2-related SRTD11 case?

Prominent limb shortening and polydactyly are presented as the primary ultrasound findings.

Why can classic thoracic abnormalities be less obvious in DYNC2I2-related SRTD11?

Classic thoracic abnormalities may be subtle prenatally, even when the condition is present.

How do genetic testing results support diagnosis and counseling in this case?

Genetic testing enables accurate identification of pathogenic variants and therefore improves diagnostic precision and counseling for affected families.

Sep 29, 2026

Uploaded by jayni