Disease relevance of GAN

• Distinction of GAN tumors from other gastrointestinal stromal tumors is based on electron microscopic findings [1].
• We conclude that a preoperative GAN-block does not offer significant advantages for postoperative pain relief in children undergoing tympanomastoid surgery [2].
• The incidence of CMV viremia was 30.8%, 50.0%, and 91.7% in the GAN, VAL, and C groups, respectively ( P=0.004, GAN vs C; P=0.07, VAL vs C; P=NS, GAN vs VAL) [3].

High impact information on GAN

• We found one frameshift, four nonsense and nine missense mutations in GAN of GAN patients [4].
• Giant axonal neuropathy (GAN, MIM 256850), a severe, autosomal recessive sensorimotor neuropathy affecting both the peripheral nerves and the central nervous system, is characterized by neurofilament accumulation, leading to segmental distension of the axons [4].
• The results, together with the recent finding of an interaction between gigaxonin and MAP1B, a MT associated protein, suggests that gigaxonin plays an important role in the crosstalk between the IF and MT networks [5].
• Analysis of aligned RNA sequences and high-resolution crystal structures has revealed a new RNA structural element, termed the UAA/GAN motif [6].
• METHODS: A total of 83 patients were prospectively randomized to 3-month treatment with oral ganciclovir (3 g/day, n=36, GAN) or oral valacyclovir (8 g/day, n=35, VAL) [7].

Biological context of GAN

• The GAN1 locus was localized by homozygosity mapping to chromosome 16 q24.1 in a 3 (4) cM interval flanked by the markers D16S3073 and D16S505 (D16S511) in three non-related Tunisian families, showing a genetic homogeneity in these families [8].
• The differences in the course of the disease between Tunisian and non-Tunisian patients suggest a possible genetic heterogeneity, which is why the present linkage has been referred to as GAN1 [8].

Anatomical context of GAN

• The gastrointestinal autonomic nerve tumor (GAN tumor) is an uncommon stromal tumor of the intestinal tract and retroperitoneum first described by Herrera and associates in 1984 [1].
• In GAN, filamentous aggregates have been shown also to occur in other cell types including cultured skin fibroblasts [9].
• CD34 was also expressed in smooth muscle (54%) and GAN (62%) tumors [10].
• GAN is a rare genetic disease of childhood involving the central and peripheral nervous systems [11].
• Confocal microscope studies of gigaxonin-transfected COS-7 cells and cultured neurones revealed that a proportion of gigaxonin localises to the Golgi and endoplasmic reticulum [12].

Associations of GAN with chemical compounds

• Group sham block-block (SB-B) received a preemptive GAN-block with normal saline before surgical incision followed by a GAN-block with 0.25% bupivacaine with 1:200000 epinephrine 1 h before the completion of the procedure [2].
• Over 50% of these proteins were reported for the first time as tyrosine phosphorylated, including gigaxonin, XIAP and CDK10 [13].

Analytical, diagnostic and therapeutic context of GAN

• Children were divided into two groups: group block-block (BB) received a preemptive great auricular nerve block (GAN-block) with 0.25% bupivacaine with 1:200,000 epinephrine before incision followed by a second GAN-block with 0.25% bupivacaine with 1:200,000 epinephrine 1 h before the end of the procedure [2].
• Treatment failure (death, graft loss, CMV disease, or withdrawal from study) occurred in 14.3%, 0% and 66.7% in the GAN, VAL, and C groups, respectively ( P=0.014, GAN vs C; P=0.001, VAL vs C; P=NS, GAN vs VAL) [3].
• GAN tumors are rare and their diagnosis and distinction from other gastrointestinal stromal tumors is based on electron microscopy findings [14].

References