Hollander W F
Am J Anat. 1976 Jun;146(2):173-9. doi: 10.1002/aja.1001460205.
Spina bifida occulta is one of the major effects of the recessive mutant "snubnose" (symbol sno). Linkage tests have located this mutant in chromosome 4. Defective spinal arch formation typically includes the lumbar and often the posterior thoracic and sacral vertebrae. There is great variation in detail, from nearly normal closure to a trough-like spinal column. Causes of the variation are not understood. Severely affected specimens may also have defective anterior thoracic vertebrae and reduced size of the sacral vertebrae, with kyphosis. The tail is essentially normal. No external lesion or myelomeningocele has been found, but there have been some instances of paralysis of the hind limbs, possibly from injury. The spinal cord seems normal as a rule, and pigmentation is normal. Embryological study has not been attempted, but the condition seems to be primarily osteogenic in origin.
隐性突变体“短鼻”（符号为sno）的主要影响之一是隐性脊柱裂。连锁试验已将该突变体定位在4号染色体上。典型的脊柱弓形成缺陷包括腰椎，通常还包括胸后段和骶椎。在细节上有很大差异，从几乎正常的闭合到槽状脊柱。变异的原因尚不清楚。严重受影响的标本可能还存在胸前段椎体缺陷和骶椎尺寸减小，并伴有脊柱后凸。尾巴基本正常。未发现外部病变或脊髓脊膜膨出，但有一些后肢麻痹的病例，可能是受伤所致。脊髓通常看起来正常，色素沉着也正常。尚未尝试进行胚胎学研究，但这种情况似乎主要起源于成骨。
