Terminal 22q deletion associated with a partial deficiency of arylsulphatase A.

Abstract

A 7 month old girl with psychomotor retardation, hypotonia, and minor malformations was found to have a terminal deletion of the long arm of chromosome 22, del(22)(ql3.31). The partial deficiency of arylsulphatase A (ARSA) and the normal level of NADH diaphorase 1 (DIAl) suggests that the ARSA locus can be regionally assigned to 22q13.31-+qter and the DIAl locus can be excluded from the same segment. This report is the third published case with a terminal 22q deletion.Partial monosomy 22 has been reported in relatively few cases. Most of them have an r(22), and there have been only two instances of a terminal deletion of the long arm.' 2 We describe here another patient with a terminal 22q deletion. Gene dosage studies of arylsulphatase A (ARSA) and diaphorase 1 (DIAl) supported their localisations on the distal long arm of chromosome 22.

Girl with accelerated growth, hearing loss, inner ear anomalies, delayed myelination of the brain, and del(22)(q13.1q13.2)

“…The result of FISH analysis and normal activity of arylsulfatase A in the lymphocytes, the gene of which is mapped to chromosome 22q13.3 [Geurts van Kessel et al, 1980;Narahara et al, 1992] indicate that a 22q13.3 segment is not deleted in her chromosome. Among the 18 previously reported patients with 22q13 (22)(q13.1q13.2) and Accelerated Growthdeletion [Herman et al, 1988;Romain et al, 1990;Zwaigenbaum et al, 1990;Narahara et al, 1992;Phelan et al, 1992;Nesslinger et al, 1994;Dohney et al, 1997;Wong et al, 1997;Schröder et al, 1998], there has been only one patient who had an interstitial deletion of a 22q13 segment [Romain et al, 1990] and no case of interstitial deletion involving a 22q13.1-q13.2 segment, as seen in our patient.…”

“…To our knowledge, however, deletion of 22q13 band has been reported in only 18 patients [Herman et al, 1988;Romain et al, 1990;Zwaigenbaum et al, 1990;Narahara et al, 1992;Phelan et al, 1992;Nesslinger et al, 1994;Dohney et al, 1997;Wong et al, 1997;Schröder et al, 1998]. All of them were a terminal deletion involving 22q13, but only one had interstitial deletion of this segment [Romain et al, 1990].…”

The 22q13.3 Deletion Syndrome (Phelan-McDermid Syndrome)

“…Intellectual impairment, hypotonia, normal to accelerated growth, absent to severely delayed speech, and minor dysmorphic features emerged as common characteristics of individuals with deletion of 22q13.3 [Watt et al, 1985;Kirshenbaum et al, 1988;Romain et al, 1990;Zwaigenbaum et al, 1990;Narahara et al, 1992]. Nesslinger et al [1994] first suggested that this was the recognizable phenotype of deletion 22q13.3, and they narrowed the critical region of overlap from a proximal breakpoint below D22S97 to a region distal to ARSA , a distance of less than 25.5 cM.…”

Prenatal diagnosis of mosaicism for a del(22)(q13)

“…2. Simple deletions detected at routine banded chromosome examination, with or withouth subsequent con®rmation by FISH or molecular marker studies (Herman et al, 1988;Kirshenbaum et al, 1988;Zwaigenbaum et al, 1990;Narahara et al, 1992;Phelan et al, 1992;Nesslinger et al, 1994;Wong et al, 1997;Yong et al, 1997;Schro È der et al, 1998); this deletion of a part of 22q13 is associated with a common phenotype of mild dysmorphisms, normal or accelerated growth, muscular hypotonia, defective or even absent speech, and mental de®ciency of moderate degree. Since the latter ®nding was reported in all evaluated patients, it has already been suggested that a gene or genes controlling the development of expressive speech maps within 130 kb off the telomere of 22q (Wong et al, 1997;Precht et al, 1998).…”

“…Although distal 22q deletions have been well documented postnatally (Watt et al, 1985;Romain et al, 1990;Zwaigenbaum et al, 1990;Narahara et al, 1992;Phelan et al, 1992;Nesslinger et al, 1994;Flint et al, 1995;Ning et al, 1996;Doheny et al, 1997;Slavotinek et al, 1997;Yong et al, 1997;Herman et al, 1988;Precht et al, 1998;Schro È der et al, 1998), prenatal diagnosis of this abnormality, particularly in the mosaic form, has not been reported as yet. We describe what we believe to be the ®rst case of prenatal diagnosis of mosaicism for a del(22)(q13) in a fetus, associated with anomalies on ultrasound.…”