Case Report: New presentation of CLIFAHDD syndrome with a novel variant in the NALCN gene and a literature review.

Background: Congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD) syndrome (OMIM #616266) is an autosomal dominant hereditary disease that can lead to the congenital contracture of the limbs and face, hypotonia, and developmental delay. In addition, it may result in growth retardation and present various clinical symptoms, such as brain atrophy, a small pituitary gland, musculoskeletal abnormalities, abnormal breathing, abdominal hernia, and abnormal facial features. Herein, we describe a novel de novo missense genetic variant in the sodium leak channel, non-selective (NALCN) gene that is associated with CLIFAHDD syndrome. Case description: This study describes a patient with varus deformities in both feet, deviation of the ulnar side of the fingers, and severe hypotonia. This patient was subsequently confirmed to have CLIFAHDD syndrome through genetic testing, which also revealed a novel missense de novo genetic variant in the NALCN gene (c.3553G > A, p.Ala1185Thr). Conclusions: Our findings further enrich the known variant spectrum of the NALCN gene and may expand the range of clinical options for treating NALCN-related disorders.

New presentation of CLIFAHDD syndrome with a novel variant in NALCN gene: A report of a rare case.

Key Clinical Message: Congenital Contractures of Limbs and Face, Hypotonia, and Developmental Delay (CLIFAHDD) syndrome is a recently described type of distal arthrogryposis which unlike other subtypes is associated with developmental delay and various neurologic presentation. Epilepsy and ataxia have been reported. We add paroxysmal dyskinesia to the clinical spectrum. Understanding the molecular mechanism can help developing targeted therapy in future. Abstract: This study resulted in identification of a novel variant in NALCN gene leading to autosomal dominant CLIFAHDD syndrome. Our patient presented with a form of nonepileptic paroxysmal dyskinesia. This is a new phenotype that has not been described previously.

Central Apneas Due to the CLIFAHDD Syndrome Successfully Treated with Pyridostigmine.

NALCN mutations lead to complex neurodevelopmental syndromes, including infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) and congenital contractures of limbs and face, hypotonia, and developmental delay (CLIFAHDD), which are recessively and dominantly inherited, respectively. We present a patient in whom congenital myasthenic syndrome (CMS) was suspected due to the occurrence of hypotonia and apnea episodes requiring resuscitation. For this reason, treatment with pyridostigmine was introduced. After starting the treatment, a significant improvement was observed in reducing the apnea episodes and slight psychomotor progress. In the course of further diagnostics, CMS was excluded, and CLIFAHDD syndrome was confirmed. Thus, we try to explain a possible mechanism of clinical improvement after the introduction of treatment with pyridostigmine in a patient with a mutation in the NALCN gene.

Case Report: A de novo Variant in NALCN Associated With CLIFAHDD Syndrome in a Chinese Infant.

Background: The NALCN encodes a sodium ion leak channel that regulates nerve-resting conductance and excitability. NALCN variants are associated with two neurodevelopmental disorders, one is CLIFAHDD (autosomal dominant congenital contractures of the limbs and face, hypotonia, and developmental delay, OMIM #616266) and another is IHPRF (infantile hypotonia with psychomotor retardation, and characteristic facies 1, OMIM #615419). Case Presentation: In the current study, a Chinese infant that manifested abnormal facial features, adducted thumbs, and neurodevelopmental retardation was diagnosed with CLIFAHDD syndrome. A trio-based whole-exome sequencing revealed that the infant harbored a de novo variant of the NALCN gene (c.4300A>G, p.I1434V). Conclusions: Our findings further enriched the variant spectrum of the NALCN gene and may expand the clinical range of NALCN-related disorders.