Preserved neurobehavioral abilities in Lujan-Fryns syndrome

Investigations of an individual with a Marfanoid habitus, mild intellectual disability, and severe social anxiety identifies PCDHGA5 as a candidate neurodevelopmental disorder gene

Marfanoid habitus and intellectual disability (MHID) co-occur in multiple neurodevelopmental disorders (NDD). Among those, Lujan-Fryns, an X-linked genetic disorder associated with variants in MED12 was the first such syndrome identified. Accurate molecular diagnosis for these MHID syndromes remains a challenge due to significant clinical and genetic heterogeneity. We present a case report of a 20-year-old male patient with MHID and severe social anxiety. A comprehensive clinical evaluation, including morphotype assessment, cognitive, and psychometric and genetic testing, was conducted to provide a detailed understanding of the patient's complex clinical presentation. Psychometric assessments revealed severe social anxiety and various cognitive and emotional challenges. Despite some autism-like symptoms, the patient's clinical presentation was more aligned with mild intellectual disability. Exome sequencing was inconclusive but identified a heterozygous de novo missense variant in the PCDHGA5 gene. This gene is not known in human pathology yet, but we also report a second patient with a syndromic neurodevelopmental disorder and a rare de novo variant which leads us to propose this as a candidate gene. Our findings emphasize the importance of multidisciplinary approach in the diagnosis and management of MHID. This case report underscores the need for objective clinical evaluations and standardized tools to better understand the complex clinical profiles of patients with NDDs. The identification of novel PCDHGA5 gene variants adds this gene's candidacy to the genetic landscape of MHID-NDD, warranting further investigation to determine its potential contribution.

Lujan-Fryns Syndrome (LFS): A Unique Combination of Hypernasality, Marfanoid Body Habitus, and Neuropsychiatric Issues, Presenting as Acute-Onset Dysphagia

BACKGROUND

Lujan–Fryns syndrome (LFS) is an extremely rare, X-linked disorder, for which the full clinical spectrum is still unknown. Usually, it presents with neuropsychiatric problems such as learning disabilities and behavioral issues in a typical combination with marfanoid features. Often, there is a positive family history for the disorder. However, sporadic cases have also been reported in males. More interestingly, there is no case of LFS presenting with acute-onset dysphagia in the English language medical literature.

CASE PRESENTATION

A 17-year-old Pakistani mentally normal school boy was admitted for the workup of acute-onset dysphagia, hypernasal speech, and nasal regurgitation of liquids. He had no neuropsychiatric issues, and his family history was unremarkable. An obvious nasal twang, facial dysmorphism, and marfanoid body habitus were found on examination. The genetic tests revealed a pathogenic missense mutation in the MED12 gene on his X-chromosome.

CONCLUSION

LFS can present as acute-onset dysphagia and in the absence of any neuropsychiatric issues or positive family history of the syndrome.

Lujan-Fryns syndrome (mental retardation, X-linked, marfanoid habitus)

The Lujan-Fryns syndrome or X-linked mental retardation with marfanoid habitus syndrome is a syndromal X-linked form of mental retardation, affecting predominantly males. The prevalence is not known for the general population. The syndrome is associated with mild to moderate mental retardation, distinct facial dysmorphism (long narrow face, maxillary hypoplasia, small mandible and prominent forehead), tall marfanoid stature and long slender extremities, and behavioural problems. The genetic defect is not known. The diagnosis is based on the presence of the clinical manifestations. Genetic counselling is according to X-linked recessive inheritance. Prenatal testing is not possible. There is no specific treatment for this condition. Patients need special education and psychological follow-up, and attention should be given to diagnose early psychiatric disorders.

Eating disorder in a patient with phenotypical features of Lujan-Fryns syndrome

We report a young patient with phenotypic, cognitive and behavioural features consistent with a diagnosis of Lujan-Fryns syndrome. He exhibited a severe eating disorder with food refusal and psychogenic loss of appetite, which led to a serious state of malnutrition. Behavioural difficulties including shyness, hyperactivity and emotional instability are present in almost 80% of the described patients with Lujan-Fryns syndrome but eating disorders have not been previously reported in this condition. A review of the behavioural problems in Lujan-Fryns syndrome and an approach to their management is discussed.

Psychopathology in the Lujan–Fryns syndrome: Report of two patients and review

We report on two new patients, the propositus and his maternal uncle, with Lujan-Fryns syndrome (LFS). One presented with mild mental retardation and both patient had Marfanoid habitus and similar craniofacial anomalies (they had a long and narrow face, small mandible, high-arched palate, and hypernasal voice) as previously reported by Lujan et al. in 1984 and Fryns and Buttiens in 1987. One of our patients had agenesis of the corpus callosum as described by Lujan. The second patient had an ascending aortic aneurysm like the patient described by Wittine et al. 1999. Both patients showed similar behavior and psychiatric disorders. In addition, we reviewed the literature for the presence of psychopathology in LFS. After studying the 32 published cases and the 2 described in this article, we found that more than 90% of the patients present with some type of psychopathology, the most frequent being an autistic-like disorder. In our opinion, the agenesis of the corpus callosum (complete or partial) and ascending aorta aneurysm are manifestations of LFS, and thus brain MRI and echocardiogram should be part of the routine evaluation. Additionally, the high prevalence of psychopathological alterations in these patients suggests the need for psychiatric evaluation at the time of diagnosis.