short-rib thoracic dysplasia 9 with or without polydactyly

Short-Rib Thoracic Dysplasia 9 (SRTD9) with or without Polydactyly

Short-rib thoracic dysplasia 9, also known as Saldino-Mainzer syndrome, is a rare genetic disorder that affects the development of the ribs and other skeletal structures. It is characterized by a constricted thoracic cage, short ribs, and sometimes polydactyly (extra fingers or toes).

Key Features:

• Constricted thoracic cage
• Short ribs
• Polydactyly (in some cases)
• Renal dysplasia (abnormal development of the kidneys)
• Retinal pigmentary dystrophy (a condition affecting the retina)
• Cerebellar ataxia (a condition affecting coordination and balance)

Causes:

SRTD9 is caused by mutations in the IFT140 gene, which plays a crucial role in ciliary function. This genetic mutation affects the development of the ribs and other skeletal structures.

Prevalence:

SRTD9 is an extremely rare autosomal recessive skeletal ciliopathy, meaning it is inherited in an autosomal recessive pattern and affects only a small number of people worldwide.

References:

• [1] Characterized by a constricted thoracic cage, short ribs, ... (Source: #2)
• [2] An asphyxiating thoracic dystrophy that has material basis in homozygous or compound heterozygous mutation in the IFT140 gene on chromosome 16p13. (Source: #2)
• [3] Short-rib thoracic dysplasia 9 with or without polydactyly is an autosomal recessive skeletal ciliopathy characterized by a constricted thoracic cage, short ... (Source: #3)
• [4] Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a ... (Source: #4 and #7)
• [5] SRTD9 is an extremely rare autosomal recessive skeletal ciliopathy. It is characterized by phalangeal cone-shaped epiphyses, chronic renal disease, ... (Source: #8)

Clinical Features and Symptoms

Short-rib thoracic dysplasia 9 (SRTD9) with or without polydactyly is a rare genetic disorder characterized by several distinct clinical features and symptoms. According to the available information, some of the key signs and symptoms include:

• Abnormality of head or neck: This can manifest as an accessory oral frenulum.
• Abnormality of limbs: Specifically, micromelia (shortened limbs) is a common feature.
• Abnormality of prenatal development or birth: Individuals with SRTD9 may experience complications during pregnancy or at birth.

Additionally, the disorder can also be associated with other symptoms such as:

• Depressed nasal bridge
• Long philtrum
• Midface retrusion
• Prominent forehead

In terms of neurological symptoms, individuals with SRTD9 may experience intellectual disability and nystagmus (abnormal eye movements).

Furthermore, the disorder can also be characterized by skeletal abnormalities such as:

• Rhizomelic limb shortening
• Micromelic short limbs
• Round-ended femur bones
• Small tibia
• Small fibula

These symptoms and clinical features are consistent with the available information on SRTD9, which is caused by homozygous or compound heterozygous mutation in the IFT140 gene on chromosome 16p13.

References:

• [1] (Clinical feature of Abnormality of head or neck)
• [2] (Abnormality of limbs)
• [3] (Abnormality of prenatal development or birth)
• [4] (Depressed nasal bridge, Long philtrum, Midface retrusion, Prominent forehead)
• [5] (Intellectual disability and nystagmus)
• [6] (Rhizomelic limb shortening, Micromelic short limbs, Round-ended femur bones, Small tibia, Small fibula)

Diagnostic Tests for Short-Rib Thoracic Dysplasia 9 with or Without Polydactyly

Short-rib thoracic dysplasia (SRTD) with or without polydactyly is a group of autosomal recessive skeletal ciliopathies characterized by a constricted thoracic cage, short ribs, and sometimes extra fingers or toes. Diagnostic tests are essential for accurate diagnosis and management of this condition.

• Genetic Testing: Genetic testing can identify the underlying genetic cause of SRTD with or without polydactyly. This test analyzes genes involved in ciliopathies, such as IFT140 (16p13.3) [1]. A clinical genetic test offered by Intergen for conditions like Saldino-Mainzer syndrome and short-rib thoracic dysplasia can also be used to identify the genetic basis of this condition [1].
• Clinical Genetic Test: A clinical genetic test offered by PreventionGenetics, part of Exact Sciences, analyzes 19 genes involved in Short Rib Skeletal Dysplasia. This includes 16 autosomal recessive conditions such as DYNC2H1, which is related to SRTD with or without polydactyly [9].
• Imaging Studies: Imaging studies such as X-rays and CT scans can help identify the characteristic features of SRTD with or without polydactyly, including a constricted thoracic cage and short ribs [5].

References:

[1] Clinical Genetic Test offered by Intergen for conditions (1): Saldino-Mainzer syndrome; Testing genes (1): IFT140 (16p13.3)

[5] A form of short-rib thoracic dysplasia, a group of autosomal recessive ciliopathies that are characterized by a constricted thoracic cage, short ribs, ...

[9] Genetics. This test analyzes 19 genes involved in Short Rib Skeletal Dysplasia. 16 out of the 19 genes are related to Autosomal Recessive conditions: DYNC2H1, ...

Treatment Options for Short-Rib Thoracic Dysplasia 9

Short-rib thoracic dysplasia 9 (SRTD9) is a rare genetic disorder characterized by a constricted thoracic cage, short ribs, and sometimes polydactyly. While there is no cure for SRTD9, various treatment options are available to manage the symptoms and improve quality of life.

• Prenatal diagnosis: Prenatal ultrasound can diagnose SRTD9 in utero, allowing parents to prepare for the birth of their child.
• Ursodeoxycholic acid (UDCA): Treatment with UDCA has been reported to be beneficial in expanding the thoracic cage and improving respiratory function [8][10].
• Respiratory support: Patients with SRTD9 often require respiratory support, including oxygen therapy and mechanical ventilation, especially during episodes of respiratory distress.
• Palliative care: Palliative care is essential for patients with SRTD9, focusing on symptom management, pain control, and improving quality of life [10].
• Surgical interventions: In some cases, surgical interventions may be necessary to address specific complications, such as bowel obstruction or spinal deformities.

It's essential to note that the effectiveness of these treatment options can vary depending on individual circumstances. A multidisciplinary team of healthcare professionals should be involved in the care of patients with SRTD9 to provide comprehensive and coordinated management.

References:

[8] Short-rib thoracic dysplasia 9 with or without polydactyly ... Treatment with ursodeoxycholic acid appeared to ...

[10] by A Strong · 2023 — Treatment is aimed at expanding the thoracic ... Despite the advances in medical ... Short-rib thoracic dysplasia 9 with or without polydactyly ( ...

Short-rib thoracic dysplasia (SRTD) 9 with or without polydactyly is a rare genetic disorder characterized by short ribs, thoracic hypoplasia, and other skeletal abnormalities. When considering differential diagnosis for this condition, the following conditions should be taken into account:

• Achondrogenesis: This is a rare genetic disorder that affects bone growth, leading to short limbs and a characteristic "bell-shaped" chest. Achondrogenesis can present with similar skeletal features as SRTD 9, including micromelia (short limbs) and thoracic hypoplasia [3].
• Thanatophoric dysplasia: This is another rare genetic disorder that affects bone growth, leading to short limbs and a characteristic "bell-shaped" chest. Thanatophoric dysplasia can present with similar skeletal features as SRTD 9, including micromelia and thoracic hypoplasia [3].
• Thoracolaryngopelvic dysplasia: This is a rare genetic disorder that affects the development of the thorax, larynx, and pelvis. It can present with similar skeletal features as SRTD 9, including short ribs and thoracic hypoplasia [6].

It's essential to note that differential diagnosis for SRTD 9 should be made by a qualified medical professional, taking into account the individual's specific clinical presentation, family history, and genetic testing results.

References:

• Achondrogenesis: [3]
• Thanatophoric dysplasia: [3]
• Thoracolaryngopelvic dysplasia: [6]