The Endocrine System and Its Disorders
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss in Understanding Medical Terms, 2020
Pituitary hypersecretion of the growth hormone somatotropin during the period of skeletal development results in giantism, an abnormal increase in the length of skeletal structures causing unusually large body size (hence the name). Acromegaly (acro = extremity, plus megaly, large), a form of gigantism that affects adults, is often caused by a pituitary tumor that produces excess growth hormone after skeletal development is normally complete. Rather than affecting skeletal length, its effects are seen as thickening of cartilage and bone with widening of the jaw, hands, feet, eyebrow ridges, and soft tissue. Conversely, hyposecretion of somatotropin results in dwarfism, the condition seen in dwarfs and midgets. Dwarfism can also result from a deficiency in thyroid hormones.
Structure and Function of Cartilage
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi in Articular Cartilage, 2017
Hyaline cartilage is also found in the ends of the ribs, larynx, tracheal rings, bronchi, ears, sclera of the eye, and nose, where it is covered by perichondrium. Another hyaline cartilage structure is the the epiphyseal (growth) plate, in the metaphysis (wider region at the end of the long bones), responsible for the elongational growth of bones. The growth plate organizes into multiple zones of differentiating chondrocytes in columns. These zones include undifferentiated cartilage cells (resting zone), proliferating cells (responsible for volume increases), hypertrophic cells (cells enlarged and aligned in columns, and beginning to undergo apoptosis), and calcified cells (where cartilage is replaced by bone). As skeletal development and maturation proceed, chondrocytes undergo terminal differentiation into hypertrophic chondrocytes, and the growth plates calcify and are eventually replaced by bone, at which point the bone stops elongating (Johnston 1997). Defects or injuries to the growth plate commonly result in shortening of the affected bone, as longitudinal growth is impaired. Long bone growth defects may lead to growth disorders such as achondroplasia, the most common cause of dwarfism.
Congenital thoracic deformities
Prem Puri in Newborn Surgery, 2017
Jeune, in 1954, first described a pair of siblings with a narrow rigid chest and multiple cartilage anomalies.50 The syndrome is also known as asphyxiating thoracic dysplasia (ATD) and thoracic–pelvic–phalangeal dystrophy.51 This is a rare autosomal recessive disorder. 52,53 Other manifestations include dwarfism with short ribs and short limbs—with radiographic changes in the ribs and pelvis. There is some association with abnormalities of the kidneys, liver, pancreas, and retina.54 Variable skeletal and radiographic severity occurs in this syndrome. Its most prominent feature is a narrow “bell-shaped” thorax and protuberant abdomen. The thorax is narrow in both the transverse and sagittal axes and has little respiratory motion due to the horizontal direction of the ribs (Figure 36.6). The ribs are short and wide, and the splayed costochondral junctions barely reach the anterior axillary line. The costal cartilage is abundant and irregular like a rachitic rosary. Microscopic examination of the costochondral junction reveals disordered and poorly progressing endochondral ossification, resulting in decreased rib length.
Pigmentary retinopathy with perivascular sparing in a SOFT syndrome patient with a novel homozygous splicing variant in POC1A gene
Published in Ophthalmic Genetics, 2023
Bilge Batu Oto, Deniz Ağırbaşlı, Oğuzhan Kılıçarslan, Gökhan Celik, Aysel Kalayci Yigin, Mehmet Seven, Hüseyin Yetik
SOFT syndrome (MIM614813) is an extremely rare genetic primary bone dysplasia disorder caused by biallelic mutations in the POC1 Centriolar Protein A (POC1A) gene. Syndrome is a severe form of dwarfism together with four major clinical manifestations as short stature, onychodysplasia, facial dysmorphism, and hypotrichosis. Arrested growth of bone and ectodermal tissues causes characteristic phenotypic features as disproportionate short stature, relative macrocephaly or normocephaly at birth, prominent forehead, midfacial dysmorphism, hypoplastic, and short fingers. Psychomotor development does not seem to be affected. Orbital manifestations like hypertelorism may be present due to affected midface anatomy (1,2). Rare retinal manifestations of SOFT syndrome have been reported to date. Herein, we report a unique case of a SOFT syndrome with novel findings of pigmentary retinopathy.
An Exploration of Sexual Health Education Among Individuals with Skeletal Dysplasia (Dwarfism)
Published in American Journal of Sexuality Education, 2018
Individuals with dwarfism have a disability and are a minority group, but they are not always viewed as such, possibly because they are seen to be living productive lives (Shakespeare, Thompson, & Wright, 2010). Many individuals with dwarfism do not identify as having a disability (Shakespeare et al., 2010). Approximately 200 forms of dwarfism exist, which affects about 1 in 15,000 individuals (Bonafe et al., 2015; Sewell et al., 2015; Thompson, Shakespeare, & Wright, 2008). Dwarfism refers to skeletal dysplasia, a class of medical conditions that involves skeletal abnormalities of bone and cartilage. Disproportionate skeletal dysplasia is when limbs are not sized to a person's trunk, and proportionate skeletal dysplasia is when the person has limbs that match the trunk, but is short in stature (Bonafe et al., 2015; Sewell et al., 2015). Achondroplasia is the most common and best studied form of skeletal dysplasia, affecting 1 in 26,000 births (Bonafe et al., 2015; Sewell et al., 2015). Each type of skeletal dysplasia is associated with a set of physical or functional difficulties, which can include spinal cord problems, obesity, chronic pain, premature arthritis, and osteoporosis (Dhiman et al., 2017; Low, Knudsen, & Sherrill, 1996; Sewell et al., 2015). Many individuals with skeletal dysplasia do not seek services for their physical pain, possibly due to feeling stigmatized by health care providers (Dhiman et al., 2017).
Cranio-cervical junction malformation causing cord compression in infant with achondroplasia: a bigger picture
Published in British Journal of Neurosurgery, 2023
S. Caratella, M. Tarazi, F. T. Tomalieh, G. Spink, S. U. A. Bukhari, I. H. Ahmad, M. M. Hussain
Achondroplasia is the most common form of dwarfism affecting 1 in 26,000 live born infants.1,2 The skull features include a narrowed foramen magnum and shortening of the skull base and clivus.
Related Knowledge Centers
- Achondroplasia
- Endocrine Disease
- Epiphyseal Plate
- Rhizomelia
- Complications of Pregnancy
- Genetic Disorder
- Growth Hormone Deficiency
- Osteochondrodysplasia
- Growth Hormone Therapy
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