Amyoplasia and distal arthrogryposis

Heterogenic Genetic Background of Distal Arthrogryposis-Review of the Literature and Case Report

Distal arthrogryposis (DA) is a skeletal muscle disorder that is characterized by the presence of joint contractures in various parts of the body, particularly in the distal extremities. In this study, after a systematic review of the literature, we present a case report of a non-consanguineous family. In our case, the first-trimester ultrasound was negative, and the presence of the affected mother was not enough for the parents to consent to us performing invasive amniotic fluid sampling. The second-trimester ultrasound showed clear abnormalities suggestive of arthrogryposis. Whole-exome sequencing was performed and an autosomal dominantly inherited disease-associated gene was identified. In our case, a pathogenic variant in the TNNT3 gene c.188G>A, p.Arg63His variant was identified. The mother, who had bilateral clubfoot and hand involvement in childhood, carried the same variant. The TNNT3 gene is associated with distal arthrogryposis type 2B2, which is characterized by congenital contractures of the distal limb joints and facial dysmorphism. In the ultrasound, prominent clubfoot was identified, and the mother, who also carried the same mutation, had undergone surgeries to correct the clubfoot, but facial dysmorphism was not detected. Our study highlights the importance of proper genetic counseling, especially in an affected parent(s), and close follow-up during pregnancy.

A rare case of arthrogryposis multiplex congenita in a 2-year-old boy case report

Arthrogryposis multiplex congenita (AMC) is an uncommon condition present from birth that is marked by a combination of weakened muscles and multiple joint contractures. We present a case of a 2-year-old boy with AMC, who was born to consanguineous parents in Saudi Arabia. He presented with musculoskeletal abnormalities of all four limbs, including symmetric contractures in multiple joints of the body, bilateral developmental dysplasia of the hip, and vertical talus. Dysmorphic features included low-set ears, chin recession, triangular face, and nevus flammeus on the face. The child also had lactose intolerance, gastritis, inguinal hernia, and right-sided undescended testis. Surgical interventions were planned after a multidisciplinary team discussion. This case report highlights the good prognosis of AMC with all four-limb involvement and the importance of a thorough physical examination and a multidisciplinary approach to the diagnosis and management of AMC.

Altered evoked responses for motor-related words in children with upper limb motor impairments

OBJECTIVE

Obstetric brachial plexus palsy (OBPP) and amyoplasia, the classical type of arthrogryposis multiplex congenita, manifest themselves as highly limited mobility of the upper limb. At the same time, according to the embodiment cognition theories, the motor impairments might lead to the alteration of cognitive functions in OBPP/amyoplasia patients. In the current study, we examined whether OBPP/amyoplasia children exhibit altered processing of motor-related verbs.

METHODS

We conducted a case-control study using clinical population and control children. Oddball series were used to elicit mismatch negativity (MMN) EEG responses. The series consisted of limb-related verbs (deviant stimuli) and matched pseudowords (standard stimuli). 27 patients and 32 control children were included in the analysis.

RESULTS

We showed that MMN waveforms differed between OBPP/amyoplasia children and their control peers in the frontal and temporal electrodes when the stimuli contained hand-related verbs. In particular, the MMN peak latency in the OBPP/amyoplasia children was significantly delayed as compared with the healthy controls. At the same time, neither series with leg-related verbs nor series of pseudowords resulted in statistically significant differences.

CONCLUSIONS

Our findings suggest altered processing of hand-related verbs in OBPP/amyoplasia children with hand-related disabilities.

SIGNIFICANCE

Our results contribute to the growing evidence in support of the theory of embodied cognition, which proposes that various domains of cognition are shaped by bodily interactions with the environment.

Distal Arthrogryposis type 5 in an Italian family due to an autosomal dominant gain-of-function mutation of the PIEZO2 gene

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is a group of clinically and etiologically heterogeneous conditions, characterized by prenatal onset contractures affecting two or more joints. Its incidence is about 1 in 3000 live births. AMC may be distinguished into amyoplasia, distal and syndromic arthrogryposis. Distal arthrogryposis (DA) predominantly affects hands and feet. It is currently divided into more than ten subtypes (DA1, DA2A/B, DA3-10), based on clinical manifestations, gene mutations and inheritance pattern. Among them, only a few patients with DA5 have been reported. It is associated to a gain-of-function pathogenic variant of the PIEZO2 gene, encoding for an ion-channel necessary to convert mechanical stimulus to biological signals and crucial for the development of joints, neuromuscular and respiratory systems. Main clinical features include multiple distal contractures, short stature, ptosis, ophthalmoplegia and, in some cases, restrictive lung disease.

CASE PRESENTATION

Hereby, we report on a four-generation Italian family with DA5. Our first proband was a newborn with prenatal suspicion of AMC. At birth, clinical findings were compatible with a DA diagnosis. Family history was positive for the mother with short stature, ophthalmoplegia, short neck, and contractures of the joints of distal extremities, and for three other relatives on the maternal side, including grandfather and great-grandmother, who all shared similar findings. Thus, we performed a next generation sequencing analysis (NGS) of the genes associated to AMC and of those involved in DA. The gain-of-function heterozygous mutation c.8181_8183delAGA (p.Glu2727del) of PIEZO2 was identified in the proband, and the same mutation was also found in the mother, confirming the autosomal dominant inheritance of the condition.

CONCLUSIONS

Our patients contribute to the current DA5 genomic database, and to a better characterization of the disease. Clinicians may have suspicion of a DA diagnosis based on suggestive (also prenatal) clinical findings, which must be then confirmed by NGS analysis. Since natural history varies widely among different DA disorders, detection of the underlying causal variant is essential for the identification of the exact subtype, and to its adequate management, which must rely on a multidisciplinary and individualized approach.

Clinical and Genetic Findings in a Series of Eight Families with Arthrogryposis

The term “arthrogryposis” is used to indicate multiple congenital contractures affecting two or more areas of the body. Arthrogryposis is the consequence of an impairment of embryofetal neuromuscular function and development. The causes of arthrogryposis are multiple, and in newborns, it is difficult to predict the molecular defect as well as the clinical evolution just based on clinical findings. We studied a consecutive series of 13 participants who had amyoplasia, distal arthrogryposis (DA), or syndromic forms of arthrogryposis with normal intellectual development and other motor abilities. The underlying pathogenic variants were identified in 11 out of 13 participants. Correlating the genotype with the clinical features indicated that prenatal findings were specific for DA; this was helpful to identify familial cases, but features were non-specific for the involved gene. Perinatal clinical findings were similar among the participants, except for amyoplasia. Dilatation of the aortic root led to the diagnosis of Loeys–Dietz syndrome (LDS) in one case. The phenotype of DA type 5D (DA5D) and Escobar syndrome became more characteristic at later ages due to more pronounced pterygia. Follow-up indicated that DA type 1 (DA1)/DA type 2B (DA2B) spectrum and LDS had a more favorable course than the other forms. Hand clenching and talipes equinovarus/rocker bottom foot showed an improvement in all participants, and adducted thumb resolved in all forms except in amyoplasia. The combination of clinical evaluation with Next Generation Sequencing (NGS) analysis in the newborn may allow for an early diagnosis and, particularly in the DAs, suggests a favorable prognosis.

Patient-Reported Outcome Measurement Information System (PROMIS) Scores in Pediatric Patients With Arthrogryposis

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is a clinical term that is used to describe congenital contractures that lead to childhood deformities. Treatment aims are to maximize function while minimizing pain and disability. Few studies have explored patient-reported outcomes in the pediatric arthrogrypotic population, particularly concerning mobility. The aim of this study was to report scores for the Patient-Reported Outcome Measurement Information System (PROMIS) questionnaire for pediatric patients with arthrogryposis with regards to mobility, upper extremity (UE) function, pain interference, and peer relationships.

METHODS

A retrospective chart review of 76 patients with AMC aged 5 to 17 who completed the PROMIS questionnaire between January 1, 2017 to March 24, 2020 was performed. Results were collected for four domains: mobility, UE function, pain interference, and peer relationships. Outcomes were stratified by type of arthrogryposis: Amyoplasia (Am), Distal Arthrogryposis (DA), and Other Diagnoses (OD). Results of subjects with isolated upper or lower extremity involvement were compared with subjects with involvement of upper and/or lower extremities. Outcomes were correlated with history of surgical intervention.

RESULTS

Children with Am and OD demonstrated moderate impairment of mobility (average: 35.2 and 35.9, respectively), while those with DA reported only mild impairment (average: 44.9). UE function was severely impaired for children with Am (average: 23.0), moderately impaired for OD (average: 33.0), and mildly impaired for DA (average: 43.4). All patient groups reported normal ranges of pain interference, as well as good peer relationships. A moderate negative correlation between number of surgical interventions and mobility scores, and a weak negative correlation between number of surgeries and pain interference scores were found.

CONCLUSIONS

Children with AMC experience limited mobility and UE function, but normal levels of pain interference and good peer relationships. The average values provided in this study will serve as a baseline from which to evaluate the efficacy of both nonoperative and surgical interventions.

LEVEL OF EVIDENCE

Level II-prognostic study; retrospective study.