Neurofibromatosis type 1 Type 1 Spinal Muscular Atrophy (NF1), also known as phakomatosis, is a neurocutaneous disorder that is most commonly of autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance inheritance due to mutations in the NF1 gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics. Neurofibromatosis type 1 Type 1 Spinal Muscular Atrophy presents a range of clinical manifestations with the most prominent features being various pigmented skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions lesions called café au lait macules (CALMs), benign Benign Fibroadenoma nerve-sheath tumors called neurofibromas, freckling of the inguinal and axillary regions, and iris Iris The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium. Eye: Anatomy hamartomas, referred to as Lisch nodules. At least half of the individuals with NF1 have learning disabilities Learning disabilities Conditions characterized by a significant discrepancy between an individual's perceived level of intellect and their ability to acquire new language and other cognitive skills. These may result from organic or psychological conditions. Relatively common subtypes include dyslexia, dyscalculia, and dysgraphia. DiGeorge Syndrome. Neurofibromatosis type 1 Type 1 Spinal Muscular Atrophy may also cause osteodysplasia and malignant transformation Transformation Change brought about to an organism's genetic composition by unidirectional transfer (transfection; transduction, genetic; conjugation, genetic, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome. Bacteriology of tumors. The diagnosis is based on the typical clinical presentation and can be confirmed with genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies. Management depends on the clinical presentation and may vary from surgical removal to chemotherapy Chemotherapy Osteosarcoma/radiotherapy for tumors, occupational therapy Occupational Therapy Skilled treatment that helps individuals achieve independence in all facets of their lives. It assists in the development of skills needed for independent living. Fetal Alcohol Spectrum Disorder and PT for motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology impairments, treatment with growth hormone, and bracing in the case of bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types abnormalities.
Last updated: 20 Jun, 2022
Café au lait macules (CALMs):
Image showing well-circumscribed, light-brown, pigmented CALMs that are commonly found in the general population. Macules can be few millimeters to several centimeters (> 20 cm) in size and may appear at birth or early life. The development of multiple CALMs may be associated with genetic syndromes such as neurofibroma
type 1
Type 1
Spinal Muscular Atrophy. Macules can be treated with
laser therapy
Laser Therapy
The use of photothermal effects of lasers to coagulate, incise, vaporize, resect, dissect, or resurface tissue.
Glaucoma for cosmetic purposes.
Axillary freckling and café au lait macules (CALMs):
Axillary freckling (a) and multiple CALMs (b) spreading over the
skin
Skin
The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue.
Skin: Structure and Functions of the trunk of an individual with neurofibroma
type 1
Type 1
Spinal Muscular Atrophy (NF1)
Neurofibromas (
NF
NF
Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area.
Necrotizing Fasciitis):
Images showing different types of neurofibromas associated with NF1.
Lisch nodules in the iris Iris The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers – the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium. Eye: Anatomy:
Image showing pigmented hamartomas that derive from dendritic melanocytes Melanocytes Mammalian pigment cells that produce melanins, pigments found mainly in the epidermis, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called melanosomes. The large non-mammalian melanin-containing cells are called melanophores. Skin: Structure and Functions
Image: “Multiple small, oval, yellow-brown papules (Lisch nodules) in the right iris Iris The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers – the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium. Eye: Anatomy” by Adams, E. G., et al AL Amyloidosis. License: CC BY 3.0Sphenoid wing dysplasia:
CT image showing
exophytic
Exophytic
Retinoblastoma dysplasia of the
sphenoid bone
Sphenoid bone
An irregular unpaired bone situated at the skull base and wedged between the frontal, temporal, and occipital bones (frontal bone; temporal bone; occipital bone). Sphenoid bone consists of a median body and three pairs of processes resembling a bat with spread wings. The body is hollowed out in its inferior to form two large cavities (sphenoid sinus).
Orbit and Extraocular Muscles: Anatomy. Note the involvement of
soft tissue
Soft Tissue
Soft Tissue Abscess seen as enlargement of the individual’s entire right side of the face.
Optic pathway glioma:
MRI images showing optic pathway gliomas, a typical finding in individuals with neurofibroma
type 1
Type 1
Spinal Muscular Atrophy
The diagnosis of NF1 is usually made clinically based on the typical clinical presentation and confirmed by genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies.